/aceg/'s Ace Combat 7 multiplayer guide v1.71, as compiled by the anons. Let's do this, buddy.

The essentials:

Parts and builds
Flying technique essentials
Camera tracking

More advanced techniques and knowledge:

Special Weapons and how to use them
Advanced tips / Stupid party tricks
PSM essentials
Countering meta builds
Gunnery
Stealth
Scoring system explanation

Goodies:

/aceg/-approved builds
Credits

Parts and builds
Before you start playing multiplayer in earnest, set your control scheme to expert, finish the campaign, and unlock the following parts (listed in order of importance). It's genuinely more important than getting more planes.

High-Speed Datalink Antenna (MSL Homing ++)
Thrust-Adjusting Steering Device 2 (MSL) (MSL Homing+)
Thrust-Adjusting Steering Device 2 (Sp.W) (Sp.W Homing+)
New Flap Actuators 3 (Pitch++)
Superior Maneuverability 2 (All manoeuvrability+)
Light Blisk 2 (Accel.+ especially under 700 kph)
Variable Cycle Engine 2 (Accel.+ especially above 1100 kph and Top Speed+)
Directional Proximity Fuze 2 (MSL Damage+)
Directional Proximity Fuze 2 (Sp.W Damage+)
Cutting-Edge Airbrakes 2 and ECU Software Update (more on that later)

These will make your life much, much easier. You WILL be able to tell the difference between a stock and a fully upgraded plane, and stock planes are dead meat in MP.
Almost every build in the game will benefit from having Flaps 3, SupMan 2, Blisk and Variable Cycle Engine (level depending on whether your flying style makes you end up to low-ish (700 kph) speeds or you stay at medium speeds). These will be your bread and butter, coupled with damage and homing parts for your build's missiles. If you're using standard missiles, Datalink Antenna will also be vital to increase MSL homing to an even greater degree. It unfortunately adds looping capabilities too, but unlike QAAMs, they are not manoeuvrable or persistent enough to be a massive threat while they loop.
If your plane has access to HCAAs or HPAAs, only upgrade them and don't bother with the standards.
When it comes to manoeuvrability, pitch rate is the single most important stat. Maximise that. After that, acceleration will allow you to actually get back in your plane's ideal range of speed in a heated turnfight, so that will be your second priority. Top speed is the last truly important stat, and it's only situationally used (e.g. when chasing down a LAAM/HVAA user). Roll rate might come in handy, but SupMan already improves it to a degree where it's not really important to upgrade it specifically, and yaw is essentially irrelevant.
Weapon parts are equally important, and Homing and Damage parts are essentially mandatory if you want to play. After putting those on, it's down to personal choice on the other buffs to apply:

faster missiles (BUT slightly less manoeuvrable) with Propellant
more missiles to throw at the enemy with Takeoff Weight Augmentation 2
an extreme edge in head-on engagements with lock-on speed parts

The ace in the hole of several dogfighting builds is Airbrakes 2 or ECU 2, two severely underrated parts (that shouldn't however be installed at the same time). The fact that they make you respectively decelerate faster and stall at lower speeds means you'll also get a much, MUCH tighter turn radius, giving you a noticeable advantage that you can use even against technically superior aircraft. With a tighter turning radius, you will get better angles for your missiles and you'll give the enemy a much, much harder time matching you if you pair it with engine parts and fly aggressively. You'll also overshoot the enemy less often. Keep in mind that having both installed at the same time is suboptimal, because they conflict with each other: ECU reduces your plane's deceleration rate, while Airbrakes increases it.
It's important to look in the datasheet (https://pastebin.com/6Uh45geR): by looking into how parts interact with the plane's stats, you'll be able to see synergies and get the most out of a build.
After that's done, we can get to the fun part.
Flying technique essentials

look up your plane's ideal cornering speed in the datasheet (https://pastebin.com/6Uh45geR) and try to stay in that range, and don't slow down excessively

Every aircraft's got a range of speed where it will turn best. Learn it to get the most out of your plane's performance. Even a mediocre aircraft will be a menace if flown right. Do keep in mind that flying too slow will make you an easier target for incoming missiles. as will PSMing.

if you're not building up speed to get back to your ideal cornering speed, use high-G turns; and for the love of god, do not fly straight!

Be responsive. Be aware. Try to understand the enemy's flying style, and when you think you understand how he flies, exploit the weaknesses you've found to get your kill. Trust your plane and fly it to the limit. Don't give the enemy a second to breathe, press in to catch them unprepared. Train your reflexes.

NEVER pitch down UNLESS it's to evade a missile in a head-on or for a very minute adjustment, and don't roll to reverse course if someone's behind you; don't try to evade missiles with blind barrel rolls!

In a close turnfight, pitching down will only waste your time, and if the enemy is close on your approximate six, then trying to reverse will only help his missiles hit you more easily. If you’re in a head-on attack and the enemy got the shot off before you, however, pitching down is useful to evade. If you decide to turn to avoid a missile, keep turning in that direction! When they're in a turn and get hit by gunfire/hear an incoming missile, a lot of nuggets stop their current turn and try to reverse course, or even constantly barrel roll futilely without regard for the incoming missile's trajectory. This actually gives the missile an easier time following them, and they die because of it.

if you hear a missile alert, drop whatever you're doing to assess where it's coming from

Situational awareness is the key to victory. Always keep your attention and reflexes up, and remember that it's okay to give up a possible shot if it means evading incoming missiles. A glance at the red indicators, then a glance at the map, and you'll be able to take action if necessary. Never panic, because:

missiles will almost never hit from the side unless you're going under 600 kph, so if lots are coming from multiple directions, show them your sides

Even Macross-tier avalanches of missiles can be evaded if you angle yourself right. As always, assess the direction they're coming from, and turn so that they don't see your rear. It is trickier with incoming LAAMs and HVAAs, which will require you to go faster to evade them even if you're showing them your sides, but it will help you survive even if an entire room wants you dead.

a good rule of thumb to make your missiles hit is to fire when you can see up the target's engines if you're behind, and refer to these webms for head-on attacks: fire so that the enemy will turn into your missile's trajectory.

When you're in a trailing position, you'll need to be as close as possible to leave your enemy no escape. Refer to this picture: https://arch-img.b4k.dev/vg/1656110964214.png or https://imgur.com/qbMdFYQ , the angle is right, but ideally you'd be even closer to ensure the enemy will have no escape.
https://arch-img.b4k.dev/vg/1637052321107.webm or https://imgur.com/q2OinVC
Notice how this buddy has forced the target to go slow, and fires when the enemy has no way of evading the attack. His target does get a shot off, but he evades by pitching down; instead the target keeps turning into the missiles and actually makes their job easier, guaranteeing a hit.
https://arch-img.b4k.dev/vg/1657584721339.webm or https://imgur.com/t7TPbtu
This other buddy is fighting a target that is going faster. Take a good look at the footage and memorise the firing angles: they're meant to minimise risk to yourself while exploiting the enemy's flight path to ensure a hit.
https://arch-img.b4k.dev/vg/1662885630004.webm or https://imgur.com/nGBSjEt
https://imgur.com/TrBTbsM
Here you can see how these angles can also be applied to special weapons: HPAAs and HCAAs are extremely deadly in head-on attacks.

speaking of missile trajectories, fire them when the enemy is at the edge of your screen or beyond (most missiles have a lock-on cone bigger than your screen): this way, the missile's curve will be more natural and it will track better

While it may seem counterintuitive at first, firing when the enemy is at the edge of your screen means that the missile will immediately start curving towards the enemy. Meanwhile, if you fire while directly behind, it will fly straight at first; the enemy will only need to turn a bit and the missile will be unable to pursue.
A missile fired with this technique will track really viciously, to the point where it would seem like looping at first glance.

try to anticipate the enemy's moves!

Being able to predict your opponent is the key to victory, so you need to be proactive and imagine what he will do next. Fly accordingly: be the first to turn on the merge (this is essentially a lead turn, the most basic of BFM can be applied here) to get a few precious moments of advantage; guess where he'll turn next and plan your own move accordingly to get an advantageous angle.

don't bother with QAAM/EML/SASM, they only teach you bad manoeuvres that either leave you extremely exposed to attack or at a terrible angle to fire on the enemy.

Obviously enough, EML is a lolcannon with a stupid hitbox and huge damage (meaning its users don't even need to fly the plane, just point their nose and shoot like a point-and-click adventure). QAAM doesn't need to see the enemy to be fired and will turn like a maniac to pursue (meaning they can just spam their missiles with no thought to angles and hope they hit). SASM's AOE means that it doesn't need to hit in order to damage the enemy, and even if the damage isn't much, it's still free points. This means that their users learn to fly like NPCs and will make them sitting ducks in an actual fight, extremely easy targets for anyone with at least two neurons to rub together.

before pulling a PSM, check who's targeting you and don't initiate the manoeuvre if someone could shoot at you

PSMs (post-stall manoeuvres like the Kulbit and Cobra) are an extremely powerful tool, but you are vulnerable while you're pulling them. Never initiate one if someone's behind you, as you'll give them a sure shot to kill you; remember to also check for other players looking at you, because nothing kills a PSMing plane like an HVAA or LAAM. As always, be aware of your surroundings and do not expose yourself needlessly.

use gravity to your advantage!

Gravity does affect your aircraft and factors in your acceleration/deceleration. You can pull tighter turns if you decelerate while climbing, because it will slow you down more than just using your airbrakes, and you'll accelerate faster when you dive. This can be used in turnfights too: if you're dogfighting on the vertical, high-G while your nose is pointing up, accelerate when it's pointing down. This will tighten your turn radius and allow you to regenerate speed faster for more high-G turning.
Target-tracking camera
Accessed by keeping the "change target" button pressed on controller, or the one referred to as "highlight target" in the keyboard control options, this feature will allow you to keep your view centred on your current target. It works best in third person, as first person's view angle is constrained by the cockpit.
There are many advantages to using it, namely

being able to track your target at all times
be aware of your target's current heading and infer where it's going to turn, or see if he's trying any funny shit with PSMs
lock your missiles earlier than normal and at safer angles because the lock-on cone of every missile is larger than the screen

Do keep in mind that your general situational awareness is slightly reduced when you're using it, which is the price you pay for much better awareness on that single enemy; don't crash while trying to follow someone!

---Now that you've got the basics, let's tackle the things that will allow you to win!---

Special Weapons and how to use them
Unless you're in a Sp.W off room or your plane doesn't get good Sp.Ws, you will do most of your work using Special Weapons. They differ greatly in behaviour, so you'll need to adjust your playstyle to employ them most effectively.

4AAM

Unfortunately, 4AAMs are not particularly manoeuvrable and they get a debuff to homing for the first second after launch, so they'll suck at close range. You can only really use them against furballs that are unaware of you, and having only four at a time won't help much with clearing them. Lob them at the furball as you close in with your standard missiles and guns. Upgrading them feels like a waste of part slots to me, considering that they don't hit often.

6AAM and 8AAM

Much better. For some reason, PA decided to buff them to the point of making 4AAMs look like unguided rockets, while 6AAMs and 8AAMs can even be used as dogfighting missiles. You can use them (especially the 6AAMs) both as dogfighting missiles and as furball-clearers. They're manoeuvrable and hit like a truck, so you'll only need a single missile to bring down an unarmoured target. Do not fire more than a single missile per target per salvo. Do not waste them by shooting them liberally, only fire them at fully-formed furballs (especially if they're going slow) or use them as dogfighting missiles. Remember that 8AAMs have a "stacking lock" feature where multiple missiles will lock onto a single target (which is a waste when a single one can oneshot an unarmoured plane), which you can counter by rapidly switching weapon until you're ready to fire.

HCAA

Think of them as standard missiles, but better in every single way: better homing, better damage, better speed. They effectively make MSLs obsolete, so you can safely upgrade them exclusively. Otherwise, you can use them the same way you use standards, though obviously with a bit more caution since >finite ammo. You should still fire your unupgraded standard missiles to keep up the pressure on the enemy when you haven't got a clear shot.

HPAA

Rewarding patience and the buddy who waits for a good angle, they'll oneshot any plane that doesn't use armour when unupgraded. Damage 2 will make them obliterate any plane, regardless of armour. You won't need more ammo if you wait for the right moment and angle to fire, but you will need practice to recognise it. Refer to the footage above for ideal timing and firing angles.

HVAA

Lob them at slow, unaware targets, and watch the points roll. They're pretty manoeuvrable for a sniping weapon, but most importantly (and obviously) they're fast as fuck. Just don't use them at short range, they've got a slight debuff similar to 4AAMs. You'll give your opponent a nasty surprise on the merge, if he doesn't think fast. Stealth will make it even safer, and people will despise your existence and hunt you down; consider a build capable of both defending itself at knife range and staying undetected at longer range. Remember, you WILL become visible on everyone's radar for a second when you fire!

LAAM

The quintessential sniping weapon. Goes really well with stealth, though you will pop up on radar for a second in any case the moment you fire. Put Range 2 on it for the true BVR experience. As with HVAAs, fire at distracted, slow targets who are already preoccupied with something else. Useless within 1km.

PLSL

Look at the guy on top of the leaderboard and go medieval on his ass, or shoot up an entire furball while they're preoccupied with each other. You're a force to be reckoned in a radius of approximately 5km, but you'll need to lead the target a fair amount, and the slightest hint of clouds will stop it. Do not mindlessly joust an EML user, or you'll get a railgun shell through your face and out your ass. If you're within a cloud, a bolt will travel 50 metres or so before dissipating into a harmless blue fart. PLSL bolts travel exactly twice as fast as your gun's shots and have a maximum range of 5km (if unupgraded), so adjust your aim appropriately. You can use both gun and PLSL at knife range to melt a plane in an instant. Practice leading the target a lot, and walk your fire as you'd do with your guns, only more so at long range!

SAAM

Keep the other guy in the circle. Mostly used as a sniping weapon, SAAM is surprisingly powerful in a dogfight if you're behind the enemy (almost 50% more manoeuvrable than a QAAM!). Its guidance system possesses two quirks, one generally useful and one situational.

if your target gets outside the circle, but then you put them back in the circle, the missile will start tracking again

This means that you can essentially have the missile slingshot back around and potentially hit the target from unexpected angles. SAAMs do loop effectively, and by using this technique, you might catch the enemy off-guard. It's also generally useful, because it allows you to turn away for a moment (e.g. to avoid incoming) and then focus back on your original target without wasting the shot and your time.

if you fire two SAAMs at different targets, and both targets are within the circle, both missiles will keep tracking perfectly fine

This is more situational, but allows you to turn SAAMs into ghetto multi-lock missiles. Keeping both targets in the circle may be tricky and becomes harder as you approach, but it's entirely possible to get them both this way.
Don't get overly focused on your current target, or you might be easy prey to other people, who'll catch you distracted!

TLS

Sniper central. Like PLSL, clouds are your biggest enemy. Unlike PLSL, using TLS means having a giant, attention-grabbing beacon emanating from your plane the moment you fire, so the entire room will usually drop everything they're doing to focus on you out of sheer awe. Do not get overly focused on a single target, be prepared to evade incoming at a moment's notice, and remember that TLS rewards a steady hand.

EML, QAAM, SASM

Don't.
Advanced tips / Stupid party tricks
Beyond the sensible tips and clever strategies, there is a variety of little-known details that can give you the smallest, most vital edge, and a slew of high-risk bullshit that will either give you the upper hand in the hardest fights or get you killed in a really embarrassing manner. It is up to you to use them in the appropriate moment.

yaw-pitching

AC7 treats pitch (up-and-down) and yaw (using the rudder to directly go left and right) as separate forces, as it should. For this reason, remembering high school physics allows us to obtain even more degrees of turning if we orient ourselves appropriately and both pitch and yaw at the same time: both forces will sum and you’ll turn harder, https://i.imgur.com/SqtRJJH.png . This might not seem like much, but every little advantage helps in a heated fight, and it is especially impactful in planes with lots of yaw authority (and can turn A-10s into a dogfighting menace from Pierre Sprey's wettest dreams).

using gravity in your turns

AC games since the PS2 era take gravity into account, and you can use it to further enhance your turning abilities by timing your high-Ging. You accelerate faster when you point downwards and decelerate faster when you point upwards, https://i.imgur.com/uqlO7il.png . Using gravity to your benefit results in an even tighter turn radius, giving you an additional advantage, and directly results in the technique below.

stall turns

Purposely stalling at the apex of a turn in the vertical is extremely risky, but it allows you to pull way more degrees out of a turn and potentially follow a much more manoeuvrable opponent; even non-PSM planes can do it, and it will surprise the hell out of your opponent. Stalling in AC7 pulls your nose down almost as fast as it did in AC2, and the game doesn’t care about the direction you are facing; you can thus exploit this fact to actively turn by stalling. The reason why this technique is in this section and not the general tips is that a stalling aircraft is a sitting duck that WILL be hit by any missile fired at it from even a less-than-optimal angle, and you need good engines to get your speed back up or you might be in an even worse position than you were before using it. Do not use it if you think someone else has a good angle on you. Some use stall turns as a general tool to get a quick edge in a turnfight, while others leave it as a last resort trick in desperate situations. The choice is yours.
PSM essentials
Post-stall manoeuvres (PSMs) allow your plane to ignore the concept of angle of attack, plus reposition as you'd like, allowing you to outturn otherwise more manoeuvrable opponents. They are powerful in a one-on-one engagement, but you are vulnerable while you're in the middle of the manoeuvre, so you'll need to always stay alert to avoid getting fucked up. PSM-capable planes are divided in two categories (which can be viewed in the datasheet (https://pastebin.com/6Uh45geR) : half-PSM (which can only pull off Cobra manoeuvres at most without chaining) and full-PSM (which allow you to PSM for longer). A good rule of thumb is that if the plane is PSM-capable but not fitted with thrust-vectoring nozzles, it's a half-PSM plane (Su-34, non-Top Gun F/A-18, ADFX-01).
Before starting, set your controls to expert (as you always should) and your High-G Turn Settings to Type B. This will make them easier to initiate and pull off.
With that done, this is how you initiate a PSM:

stay around 400 to 500 kph
hold the acceleration button (throttle up)
press brake + pitch up

And congrats, you're in a PSM. When you want to stop the PSM ("cancel" it),

pitch down

And you will return to normal flight, cancelling the PSM in whatever state it is.
For reference, PSMing will be divided in phases depending on the plane's current behaviour. The phases are called Drift and Boost. Drift is the initial part, when you're moving in a straight line (the same direction you were going towards before starting the PSM) but can turn the plane's nose to your liking except downwards (allowing you, for instance, to plan your next move or line up for guns), and lasts until you've turned more than 90 degrees. Boost follows immediately after, and is the phase where the plane will start to move towards the direction your nose is currently pointing at. When boosting, you'll be accelerating very fast while maintaining the enhanced mobility (thus "boosting"). Drifting is mostly a setup step (for either a shot or a following move), while Boosting is what allows you to really outturn someone.
You'll notice that while the plane's nose can turn extremely quickly, the aircraft itself is going straight until you've rotated more than 90 degrees, after which you'll start to move towards the direction you're pointing at. This is the main limitation of PSMs: while you can outturn anything else in a duel, you will be vulnerable to players outside said duel, who can shoot at you with impunity. This also means that if you PSM while the enemy is directly behind you, the only thing you'll get is a missile up your arse.

do not PSM if the enemy has a good angle on you, you'll be a sitting duck
never PSM if you've got someone close behind you
be careful if someone is packing HVAAs or multi-lock weapons

A way to make PSMs even more powerful is Chaining, which is basically making a combo out of PSMs. It works like this:

initiate a PSM normally
cancel once (this can be done at any point) or wait for the PSM to end naturally
quickly PSM again

You can repeat this process as often as you want, as long as you're still below 500 kph to initiate the PSM again. REMEMBER: your throttle still works while you're in the PSM, so you can manage your speed to your liking while in the manoeuvre!
PSM chaining allows you to do things such as fly backwards (BKF), plus benefit from the effects of PSMing for longer. As such, by chaining, you can keep the advantages of a PSM for as long as you want. There is literally no disadvantage, beyond the usual ones that come from simply fighting at slow speeds - and even then, due to PSMing being weird, enemy missiles may become retarded and miss you anyway (still, don't count on it).
BKF is useful because it allows you to keep your nose pointed at the opponent while actually moving away from him, so you might get a shot off (gun or missile) while in a position of relative safety.
To BKF:

PSM normally
turn until you're going backwards
cancel, then immediately initiate another PSM (after all, you're chaining)
keep chaining as long as you like
Countering meta builds
The unholy trinity of QAAM/EML/SASM are a pain in the ass, but even they can be beaten with some subterfuge and specific builds. They will still have the advantage, and a meta user will still give you a hard time if he's got half a thought going through his head, but goddamn if beating them doesn't feel good. The first two in particular will be your biggest problem.

EML

The elephant in the room. Oneshot, no warning, and it's got a busted hitbox. When we say the hitbox is stupid, this is what we mean: https://arch-img.b4k.dev/vg/1654815510647.webm or https://imgur.com/v5ye3qz . To top it all off, it is always mounted on PSM-capable planes. Your overall chances of winning a fight with an EML user depend on the gamemode, the presence of other players, and most importantly the enemy's turning ability. We will assume the worst possible case: a 1v1 against an EML-02. It's fast, it's manoeuvrable, it PSMs.
With that said, even something like this has shortcomings for you to brutally exploit.

7 second reload time

Your biggest advantage over an EML user, and the easiest one to capitalise upon; at the same time, in order to exploit it, you either caught him shooting someone else or you were lucky he missed you. As you are free to shoot the enemy while it's reloading, force a head-on attack to get the best chances of hitting and killing him. Don't spend too much time at low speeds unless you're in a PSM-capable plane, or he will PSM and get on your tail with ease, or even try to gun you down like a flying turret!

requires the enemy to put his nose on you, and thus needs predictable manoeuvres

Both a tremendous advantage and a slight disadvantage depending on the situation, the fact that it's a point-and-click adventure when the enemy can point himself at you also means that he will waste shots if you deny him the appropriate angle. Again, unless you're in a PSM-capable plane, do not go too slow when fighting the enemy, as it will give him an easier time aligning a shot, or even worse, you'll be in his PSM window and then he'll have free reign over the laws of physics.
By the way, this should be a given, but it also means that you need to jink a bit when first approaching the enemy. If you just go towards him on the merge, without doing some basic manoeuvres to throw off his aim (like a lazy barrel roll at full throttle), he'll snipe you from 5 miles away because you're pointing directly at his nose.

since those manoeuvres also require some room to be pulled, fight close to the ground and use terrain to your advantage to try and deny them

A PSM that might give the enemy the perfect angle to shoot you may not be possible when you're close to the ground, or at least will require the enemy to be more careful to avoid slamming into obstacles. Exploit that mercilessly. Be daring in your flying, capitalise on the danger of crashing and you might make the enemy's usual manoeuvres unfeasible.

Fight like a lion.

When it comes to playstyle, your best bet of winning such an engagement is surprising the enemy with your moves, and doing so with rabid, unrestrained aggression. Do not let the enemy breathe for a millisecond. Catch him with his pants down when you can and keep the pressure on, while being mindful of the speed at which he may pull a PSM. If you see the enemy is getting the upper hand, only then should you disengage to build some distance and try again. Ironically, a head-on attack will usually be your best bet of killing him: while it does expose you to his railgun, he is also going to be exposed to your own missiles. If you can get an advantageous angle, you'll win that joust.
At least in my experience, a build that can get the shot off in a head-on before the enemy can get the EML to bear on you will be your best bet for survival at worst and victory at best. As an example, below is a HCAA Typhoon build made to exploit that fact, which can also be applied to the Rafale and F-15J.
https://arch-img.b4k.dev/vg/1663685464459.jpg or https://imgur.com/1eO1SUF
Many HPAA planes are able to PSM to level the playing field, and the F-15 S/MTD will also outmanoeuvre the Wyvern at all flight regimes.

QAAM

The crutch weapon par excellence.

enormous lock-on cone extending way past the aircraft's nose
extreme manoeuvrability, jumping off the rail in an instant and tracking like mad
extreme persistency, especially if they equipped Flight Time 2 (Ramjet) to give them even more flight time
high damage, will oneshot most planes without Armor 2 (Bulletproof Fuel Tank) and leave the others at 90% damage

All of this adds up to a weapon that requires no positioning skills, no planning, and no dignity. So how do we counter this? The method for killing the launching platform depends on how aware the enemy is, while dodging the weapon itself is just a matter of keeping up your energy. Again, we will assume the worst-case scenario, in this case a QAAM-22 that knows how to PSM.

unless you're definitely behind the QAAM player, assume he can lock and shoot a missile at you

The off-bore capabilities of QAAM are unparalleled. Coupled with its extreme persistency, it translates to a weapon that requires you to be always alert and on the lookout. Expect constant missile locks and alarms blaring in your ear.

no matter what, keep a decent pace so that you'll have energy for high-G turns

On top of remaining in your plane's ideal cornering speed window, keeping your speed up means that you'll always have the energy to high-G when the missile's indicator is right behind you. Despite its stats, the rules for evading standard missiles still apply to QAAM, and no missile can keep up with a high-Ging plane. As long as you can keep doing it, it is enough to survive a barrage.

keep your awareness up, those shits loop!

QAAMs are persistent, they loop when they miss and will keep tracking you for ten seconds even without the flight time part (which adds five more). Glance at the minimap and the indicators to ensure the missiles are not on your dead six, high-G when they are, and don't get overly focused on dodging! The enemy will keep launching one every 4.5 seconds (and that's ignoring any additional standards he can launch) and so your focus should always be on getting him.

avoid head-on attacks unless you can reach a really safe angle

They've got better tracking than any other missile, a bigger lock-on cone than any other missile, and a single one will do a ton of damage or kill you outright. In order to win such a head-on, you would need to position yourself much more carefully than usual, and pass at high speed to further reduce the chances of getting hit.

if the enemy exploits the wide lock-on angle too much, he might actually leave himself wide open to your guns!

It's true that QAAM users can shoot at you from any angle, but at the same time, remember: if he's firing from the very edge of his lock-on cone, he's leaving his sides or top in view of your guns! An extreme off-bore shot for him might translate to a perfect angle for deflection gunnery for you, so get in close and go to town with the cannon to chew him up. Even if he survives it, it will do some good damage, and it might shake him up to the point where he'll commit a graver error for you to exploit.

SASM

Rather than murdering you without effort, the SASM user turns the match into a score attack mission because he can farm points without effort.

the wide AOE means that it doesn't even need to hit to damage the target, essentially getting points for free
the explosion itself deals half the damage of a standard missile, which doesn't sound like much, but it takes only two salvos to kill an F-15C without Armour 2
if it does hit, a SASM inflicts as much damage as a QAAM from the impact plus the explosion on top of it, oneshotting every single plane without Armor 2 installed

What this means is that the SASM player can just shoot at the player in first place when he's distracted and get free points, because unless he's going really fast he will at least get hit by the explosion. Assuming that the target is a Su-35S with three stars (see score system section below), a SASM user can reliably rack up 6,5k points per salvo and speed off before receiving retaliation.
Unless you actually get hit square in the face by the SASM, it's unlikely that its user will kill you unassisted. Rather, he will target players that are already damaged to ensure a kill and get even more free points. With all that said, it's time to think up ways to counter it.

check your radar to see if someone is approaching the furball at high speed.

As always, awareness is the key to victory, and SASM users specifically target unaware players to ensure a hit. Deny them their free points by keeping your speed up: a slow target is more likely to be grazed by the missiles, which will allow them to detonate and inflict damage.

if he's approaching fast and you cannot assure you'll hit him, fire when he's as close as possible and at the edge of the lock-on cone: your missiles will pursue more persistently and he'll be forced to evade (and thus lose speed) or die

Your missiles will pursue more persistently and thus force him to jink. This will cost him time, attention, and precious speed; exploit this opening to close the gap and go to town with him.

you can attempt head-on attacks and consistently win them, but expect to take at least some damage if you do

SASMs track about as well as normal missiles, but their users tend to fire without any regard towards angles and probability of hitting, relying instead on the AoE to progressively damage you. This is doubly valid in head-on attacks, as you will pass closer to the enemy missiles and thus it's even more likely to trigger its proximity explosion. However, this can also work in your favour: given that most do not actively try to get in an advantageous angle, you can reach a favourable position in a head-on attack (as described earlier in the guide) and reliably kill them in a single pass.
If you are close enough to get a lock but he keeps circling to evade your missiles, with no attempt to shoot back at you, you have three options:

gun him down

Someone stuck in a turn presents a large, nice target to practice your deflection gunnery.

try to close as much as possible and fire your missiles from a lag pursuit position (near the edge of your screen)

The same trick described multiple times in this guide works even in a close fight. Your missiles will track more persistently and give you a higher chance to hit. The closer you are to the target, the less you'll need to put him near the edge of the screen.

try to get a different angle and try again

If you simply cannot hit the target, then use your current advantage to reposition yourself for an easier shot.

Darkstar

The Darkstar is the go-to choice of those who don't want to engage in a dogfight. It can simply outrun most missiles you throw at it, and it gets PLSL (both as guns and a separate Sp.W, so basically outgunning anything short of EML if he's packing these four PLSLs) and SASM (meaning that they can just fly like cowards and still rack points). We'll only count the case of a Darkstar that knows he should always keep his speed up: a Darkstar attempting to dogfight is usually a self-solving problem.

bring TLS or PLSL

You can't outrun light (or Star Wars blasters), so as long as there aren't any clouds in the way, they're the surest remedy to the problem. TLS in particular is the best since it's actually hitscan, while PLSL still needs to lead the target a considerable amount. Look at which Sp.W he picked when the match starts, and if he's picked PLSL too, be really fucking careful if he's coming towards you: you are NOT going to outgun four PLSLs on the merge, though you might get a mutual kill. It's best to shoot him as he's running away, right after predicting and avoiding his attack (and thus when he's still close enough) or when he's pointing at someone else in the furball and approaching.

bring HVAAs or LAAMs

He can't outrun these either, though he can flare them. They are best used on the merge and when he's speeding away, and he might not expect it the first time. Put New High-Energy Propellant (Speed 2) on them to absolutely ensure they'll catch up, and maybe Electro-Optical Hybrid Sight (Range 2) to enhance your locking range. You don't need Ramjet (Flight Time) because they're fast missiles that will quickly catch up with him.

don't point directly at him, but lead the target so that you'll be as close as possible when you fire your weapons

All the weapons here will benefit from being used at shorter ranges, so you should optimise your flight path to intercept the Darkstar and fire at the shortest possible distance.

don't let him distract you from the rest of the room!

Yes, Darkstars are powerful, but there are also 6 other people in the room who are shooting at each other and racking up points. If you get overly focused on the Darkstar, then someone else might outscore you and win! You should always keep your awareness up for convenient targets, and your build should be able to kill other people too. Remember that in a BR, if you just can't kill a guy, you can just evade him and outscore him. Always gauge each target's worth and difficulty, and decide which one to kill based on your evaluation.
With this in mind, something like a F-15E with TLS, the tried and true PLSL-57, or a MiG-31 with either PLSL or LAAM will make short work of a Darkstar and the rest of the room. If you're in an unlimited Sp.W off room, then put Speed 2 on your MSLs and lead your target a lot.
Gunnery
Ace Combat 7's guns are misunderstood. Their range is 1700 metres, more than what the gunsight shows you, and they're capable of handily destroying any target with a sustained burst. They are as powerful as the gunsight is unsuitable for dogfighting. Think of it as a WW2-era gyro sight: it shows the right direction to lead your shot, but you need to lead your target a lot more than what it shows you in order to hit. A far more intuitive way to aim is to take advantage of your infinite ammo and "walk your fire":

see where the tracers are going
apply a correction accordingly
watch as the enemy is shredded in less than two seconds of sustained fire

If you do find the pipper to be more convenient, then a good rule of thumb in a turnfight is to use the edge of the pipper as an initial reference instead of the central dot, and lead the target even more than that, roughly twice as much as the reticle tells you.
Given that your guns have infinite ammo, the only real disadvantage to constantly shooting is that you'll constantly appear on the radar regardless of distance, even if you're in a stealth plane.
Stealth
Ḯ̸̧̖̠̗̍̉̌ ̶̺͇̗͐̿S̸̢̨̰̟͌͋́̕Ē̴̛̳̟͍͘ͅE̷͖̗̬͙̾ ̵̭̟́̌Y̵̞̺͕͚̋̇O̸͚̼͎͑̂̋̽U̶̲̍̂̚
In AC7, stealth works through levels, from 0 to 10, that increasingly affect the enemy's ability to spot you on radar. Stealth will affect enemy detection by:

hiding you entirely at a distance
making you fade into view when approaching, instead of instantly appearing on the enemy's scope
hiding you when you are in a cone behind the enemy, the size of which will depend on the exact level

All aircraft will have a native stealth score, which can be looked up in the datasheet and is obviously higher for stealthier ones IRL. Things like the Phantom, Eagle, or Foxhound get a native stealth score of 0, while the F-35 or the FALKEN get a native 6, the highest vanilla score possible. On top of that, the separate stealth parts will add 2 and 5 levels respectively to the plane, so a F-22 (native lvl 5) with Stealth 2 will have a combined level 10 stealth.
The effects of stealth are summed up in this chart (https://arch-img.b4k.dev/vg/1683039631708.png or https://imgur.com/9RLCON7 ) from the datasheet, where

start displaying

The distance at which you will begin appearing on the enemy's HUD, gradually fading into view. Beyond that distance, you are completely invisible.

fully displayed

The distance at which your target box is fully shown to the enemy on his HUD. Beyond that distance, the enemy won't be able to use the target-tracking camera to actively track you, and your target box is less conspicuous on the HUD than a non-stealthy enemy's box.

Back Blind angle

The size of the cone behind the enemy where you will be invisible to him. If your level is high enough, it may even cause the enemy to lose track of you after passing him during a close dogfight, potentially giving you a moment to surprise him.
Stealth is mostly used in BVR builds (LAAM and HVAA) to make hunting them down more difficult- after all, it's hard to kill the guy who shot you if you can't even see him. Adding range parts to these Sp.Ws will make this strategy even more effective, potentially allowing you to fire your weapons beyond the enemy's radar range. However, no matter what you do, you WILL pop up on everyone's radar for a second when you fire any weapon (including your gun!), so these builds rely on surprise and an extremely cautious playstyle, often turning tail the moment someone figures out where they are and comes for their blood.
Score system explanation

Every player has a base score value based on the cost rating of their aircraft. The exact cost/score table can be found here: https://arch-img.b4k.dev/vg/1656114430836.png or https://imgur.com/kopFbsp
However, the actual amount of points you get is scaled based on the ratio of your aircraft cost to that of the other players. Flying a higher cost aircraft will reduce the points you receive, and conversely flying a lower cost aircraft increases the points you receive. For instance, if you destroy a plane that has 300 cost less than you do, 95% of the original score calculated is given.

Score difference between planes and percentage of score given:
0: 100%
100: 100%
200: 100%
300: 95%
400: 92%
500: 92%
600: 86%
700: 72%
Any more than a 700 point difference and the score calculation given is still 72%.

You get up to 70% of a player's score value for dealing damage, and the last 30% for actually scoring a kill.
What fraction of the 70% you get is simply (damage dealt) / (maximum HP). This means that equipping Bulletproof Fuel Tank (which increases your max HP) effectively reduces the amount of points you give out whenever you get hit, as long as you're not dying in one hit (from, say, HPAA or EML).
Each star next to a high scorer's name increases their point value by about 50% per star. That means that three stars turns your 10k F-15C into a 25k F-15C.

In BR:

0~3 players: No stars are awarded
4~5 players: 1 star for 1st
6~7 players: 2 stars for 1st, 1 star for 2nd
8 players: 3 stars for 1st, 2 stars for 2nd, 1 star for 3rd

In TDM:

Stars are awarded to both teams, according to how many players there are on that team
Last place within that team gets 0 stars, and each player above them gets an extra star as you move up in score

So even if the scoreboard in TDM is:

Alpha 1 100k
Bravo 2 80k
Bravo 4 70k
Bravo 1 30k
Bravo 3 20k
Alpha 3 15k
Alpha 4 5k
Alpha 2 2k

Then Alpha 3 will still have 2 stars, and Alpha 4 will have 1, despite all of Bravo outscoring them. However, low scoring players can still contribute by tying up enemies, evading their attacks and not giving out points, while their teammates hit those enemies while they're distracted.

/aceg/-approved builds
The buddies have come up with many builds and tactics to use them effectively, focusing on making them enjoyable to use without sacrificing strength in a fight. Included here are the main weapons used by the build, the buddies' remarks on how to employ these planes, and the reasoning behind their choice of parts. The builds listed here are sorted by increasing CST.
Remember: many of these builds can be applied to a good variety of aircraft!

1950 MiG-21bis MGP

https://arch-img.b4k.dev/vg/1721580847208.jpg

Despite being dismissed as an early-game plane by most players, the MiG-21 is actually among the most maneuverable aircraft in the game.
Combine that with the power of MGP, and you can obliterate any other plane in the sky in less than half a second.

Acceleration lv2
Acceleration/max speed lv2
Pitch lv2
SupMan lv2
Airbrake lv2
GUN Damage lv2
GUN Range lv2
GUN "Precision" (Hitbox) lv2 [---Editor's note: it doesn't increase hitbox size! According to the stat sheet, it reduces shot spread. You're better off using another part, such as pitch stability, to make the plane less twitchy.---]

Yes, this is just my Su-37 build again. But it just works™, okay?

Why Pitch lv2 though?

With Pitch lv3, the Fishbed becomes way, way too twitchy to hit anything with guns. Pitch lv2 counteracts that, while still making the Fishbed maneuverable enough to compete against the average Unlimited and 2500 builds. [With a stability part, you might be able to rock Flaps 3!]

2090 MiG-29A MSL

https://arch-img.b4k.dev/vg/1658138545693.png or https://imgur.com/IGAMXrh

All you need is a Mig and and some MSL.
Blisk 2
VCE 2
Flaps 3
SupMan 2
MSL Damage 2
MSL Speed 2
MSL Homing 2
Datalink

2130 MiG-29A HPAA

https://imgur.com/a/6sZdWR9 or https://imgur.com/bJfOghI

Here's a more slightly more readable (and up-to-date in terms of what I fly nowadays) screencap.
Blisk was chosen over VCE specifically due to the higher acceleration (despite the descriptions being the same), Cutting-Edge Airbrakes to make low-speed energy fighting easier, New Flaps and SupMan are bogstandard, Cutting Edge Large Flap had some kind of reasoning behind it, but I kinda forgot. [---Editor's note: Do not use that part! We thought it would give increased deceleration, but it turned out to be false!---] BFTs are sort of a crutch, but you are a paper mache plane if you don't have BFTs on the 29 as well (many, and I mean many missiles will OHKO or 2HKO you) but I've mostly relied on dodging. DPF to OHKO Wyverns and tougher bastards, High-Energy Propellant and Steering Device to make up for the HPAA's many failures. Takeoff Weight Augmentation is another "crutch" in that 22 HPAAs are generally just barely enough to get you through a normal time limit lobby, if you aren't being extraordinarily shrewd. Having extra missiles would be useful for a fledgling HPAA user though.

2200 F-2A HVAA

https://arch-img.b4k.dev/vg/1734469921458.jpg

Surprised there's no F-2 featured, it's a nice and versatile little plen especially in lower cost rooms. You've probably seen pic related in action if you were around for the last few shootouts.
Flaps 3
SupMan 2
MSL Damage 2
MSL Homing 2
Sp.W Damage 2
Sp.W Homing 2
Anti-Stealth Microwave Radar
Datalink

2330 F-15J HCAA

https://arch-img.b4k.dev/vg/1719699705344.jpg

A tweaked version of my PLSL F-15C build, meant for the J w/HCAA. Keep in mind I haven't tested it yet.

Acceleration lv2
Airbrakes lv2
ECU lv2
Pitch lv3
SupMan lv2
SPW Damage lv2
SPW Speed lv2
SPW Homing lv2

I noticed that I struggled to pull High-Gs with my C build, and since this build is an Eagle build for dogfights, I swapped Max Speed and Acceleration for ECU. This change should make this F-15J a much better dogfighter while still retaining some of the hit-and-run capabilities of my F-15C.

2340 F-15C PLSL

https://arch-img.b4k.dev/vg/1690053881947.jpg or https://imgur.com/T23Z0l2

In the meantime, I'll post the PLSL F-15C build I just used. It managed to keep up with what appears to be the MiG-29 build from the MP guide, so I think it's pretty good.

Acceleration 2
Airbrake 2
Max speed 2
Pitch 2
SupMan 2
Laser hitbox, range and damage 2

It's made to be good at both boom and zoom and dogfighting.

2400 Su-37 HPAA (UPDATED)

https://arch-img.b4k.dev/vg/1689886388061.jpg or https://imgur.com/0bcL6Ga

I'm finally done with my Su-37 build for AC7 MP. Here are the parts:

Acceleration lv2
Acceleration/max speed lv2
Pitch lv3
SupMan lv2
~~Gun damage lv1~~ Airbrake lv1 (Update!)
SPW damage lv2
SPW speed lv2
SPW homing lv2

As with most Su-37 builds, this one excels at punishing sloppy play from nuggets. You'll only need one or two good shots (or machine gun bursts) to shoot down whoever you're targeting.
UPDATE:
One shot, one kill
Contrary to many other HPAA builds, I use SPW damage instead of SPW reload to counter lv2 armor shenanigans while still using one missile. You might have to wait longer for a window, but if the missile hits, your opponent will die no matter what.
Max speed and acceleration and accelereation lv2 fixes one of the 37's biggest flaws and turns it into a great energy fighter, which makes the build viable even if you don't know how to PSM.
Airbrake lv1 might not seem like much, but it gave me the edge I needed to counter Typhoonanon's excellent Typhoon build.

2400 Rafale M HCAA

https://arch-img.b4k.dev/vg/1675558829806.png or https://imgur.com/0DmPZBO

Never stalls, always ready to fire. ECU Software Update is the important part. Lower Stall speed means you can maintain high-G with a tight radius turns longer than opponents. Vulnerable at high speed since ECU also reduces deceleration in high-G turns. Ideal for aggressive close-range fights at low speeds, exactly what the Rafale excels at. Especially useful in a 1v1 or prolonged turn-rate fights and against PSM users, all low-speed situations.

2400 Typhoon HCAA (can also be applied to Rafales and F-15Js)

https://arch-img.b4k.dev/vg/1724854779532.png or https://imgur.com/a/ZZw0qAU

An attempt to counter meta and PSM users. It's meant to catch the enemy by surprise, or buy you time to reposition and try again. You'll only use HCAAs and your gun to kill people, but you can fire standard missiles to increase the pressure on the opponent and increase the probability of mistakes on his part.
SupMan 2 and Flaps 3 are essential in any build. Blisk 2 increases acceleration, especially at low speed. Airbrakes 2 and ECU 1 increase deceleration and stability, especially when high-Ging, to minimise turn radius and thus give you a bit of a positional advantage even against opponents with a better turn rate. Homing and Damage are obligatory on any missile, and make HCAAs especially vicious. Multiple-target threat level detection will ensure you'll get the first shot off in any head-on engagement.
This build requires you to be both extremely aggressive (on the merge and subsequent turns) and aware of both your speed (to avoid stalling) and enemy positioning. Head-on attacks are your best friends against almost anything, only QAAMs are better in that role (and you're a buddy, you don't use QAAMs). Fire your missiles at the edge of the lock-on cone unless you're close enough to see up the enemy's engines (thus only if you're behind him).

2550 Su-35S 6AAM

https://imgur.com/a/TYt3fNh

Posting my general pub build for the Su-35S before taking a nap. It's funny how I used to get scared whenever CIC-ranked players use these. Avoid firing blindly at fur balls since 6AAMs are your only viable weapon.
Blisk for PSM stability and Lv1 Ailerons for additional responsiveness. I prefer putting High-Energy Propellant to give 6AAMs significant chasing capability against DarkStars and MiG-31s. Otherwise, I use Sp.W lock-on speed for 1v1 PSM duels. Takeoff Weight Augmentation is a decent option, too.

2620 MiG-35D 6AAM

https://arch-img.b4k.dev/vg/1719356408828.jpg

And here's my MiG-35D build before I go to bed.

Acceleration lv2
Acceleration/max speed lv2
Pitch lv3
SupMan lv2
Airbrake lv1
SPW damage lv2
SPW speed lv2
SPW homing lv2

Yes, this is just my Su-37 build again.
Thanks to 6AAM though, it becomes quite versatile, since they can be used at both close and mid-range. This means you can seamlessly switch from boom and zoom to dogfighting and vice-versa.
Keep an eye on your ammo though, you have just barely enough missiles for a single match.

2630 F-15 S/MTD HPAA

https://arch-img.b4k.dev/vg/1659824808498.jpg or https://imgur.com/deG7YD7

here's what i'm using. my choice for Cutting-Edge Large Flap is to tighten my turn radius more [---Editor's note: We realised it didn't work that way! Use another part instead!---]. combined with airbrakes, i can actually keep up with most Rafale's in this thing -- it's insane

2670 YF-23 HVAA

https://arch-img.b4k.dev/vg/1719354952198.jpg

So I came up with a YF-23 build for Unlimited rooms.

Max speed and acceleration Lv2
Max speed Lv2
Pitch Lv3
SupMan Lv1
Stealth Lv2
SPW Damage Lv2
SPW Lock-On Range Lv2
SPW Homing Lv2

A fairly basic build, but it works well most of the time.
Stealth Lv2 is mandatory here, especially since the YF-23 already has a high innate stealth stat. With it, you're practically invisible... Until the lobby starts paying attention to the guy sniping them. It also has the benefit of keeping surprisingly persistent Typhoons off your tail for a while.
Which is where Pitch and SupMan come in. They make evading missiles much easier. If, in theory, your opponent uses an especially shitty build, you can even dogfight with it!
The rest is bog-standard. Lock-On Range lets you attack from further away, and Homing and Damage are mandatory on any missile build.
Not recommended in practice.

Credits
Many thanks to OriGinS, Ali, Nathan, and Trinity for helping with the PSM section.