SUPER MEGA DATADUMP ACTION
Axioms of Mechwarrior 3-This game uses old netcode. Lead ahead of the person to hit them if they move quickly. You gotta hit them on THEIR screen, not yours. A 200ms latency means you must place the shot so it "hits" them 200ms later.
-Jump Jets on everything. The only excuse not to is a Stock match.
-Customize your controls to something you like, the default has you reaching all over the place. Scroll down for a guide to important stuff you should remap.
-When it comes to gear, it's pretty much Clan or gtfo. Mechs, on the other hand, are a different story. Also, Double Heatsinks only, there is absolutely no reason to give singles the time of day.
-Don't put important stuff in your arms unless you must. They're really really fragile. Every other section renders its equipment immune to destruction. If you can avoid putting anything in there, just strip out the armor to give yourself more tonnage to play with.
-Ammunition always goes in your arms. Why? Even if the arm is destroyed, you don't lose the ammo. One of many quirks in this game.
-On that note, turn
ON the "Relaxed Jump Jets" function in your options. This unlocks the directional Jump Jet controls, which you should always use.
-Heat makes you die. If a shot will take you past full bar, chances are you're going to blow up instantly.
-Movement is life. Fast is good, but varied speeds and directions are best.
-Missiles hurt. A lot. Run quickly to the side of the missile path, or hit your jets. Streak SRMs can be very hard to avoid like this, but it is possible.
-Expecting missiles? Bring ECM. Reduces lock-on speed, as well as effectiveness of missile related equipment (NARC doesn't even work at all). Bring some AMS too, if you can. If you're a fat mech, get good with the JJs, cause you'll need them to live no matter what.
-Everyone gravitates toward Pulse Lasers for some reason. While they are a lot better than they were on 1999 56k modems, they're still outclassed by ER Lasers. They do the same damage at a slower pace, but weigh twice as much and require a constant aim to work.
-Mechs without Torso Twists (Blackhawk, Cauldron Born) are awful due to easily being outflanked. Arm swivel just isn't enough to make up for it. The Light mechs are actually ok thanks to immense speed, but you must be an ace pilot to wield them.
-The Supernova is an awful Stock mech choice that everyone seems to gravitate towards. ER Large are weak weapons, and the Supernova is slow. You'll just get chewed up by everything else.
Important Controls you should make easy access to-Turn Left/Right
-Jump Jet Forward and Back
-Flush Coolant
-Torso controls left/right/up/down (can be handled by mouse)
-Lock Zoom reticle
-At least 0% and 100% throttle
-Reverse
-MASC
-Next Weapon Group (probably should be right click)
-Shoot (left click

)
Controls that would be wise to have easy access to
-Other speeds to make it easier to vary your speed
-Target under reticle
-Toggle Torso Mode (A.K.A. lock/unlock reticle)
-Freelook (A.K.A. arm movement)
-Jump Jet left and right
-Center Legs to Torso (can pull off amazing turns if your execution is good)
My Controls
1 - 0% Throttle
2 - 30%
3 - 60%
4 - 100%
A - Turn Left
D - Turn Right
S - Jet back
W - Jet Forward
Q - Jet Left
E - Jet Right
R - Reverse
T - Target Next Enemy
F - Flush Coolant
G - Get up
Z - Lock Zoom Reticle
X - Chat
Shift + X - Team Chat
C - Center legs to torso (I'm not good at this tough maneuver or anything)
V - MASC
Tab - Toggle Torso Mode
Shift + Tab - Freelook
Mouse - Torso/Reticle
Left mouse button - Shoot
Right mouse button - Next Weapon Group
Wheel Click - Target Under Reticle
It takes some getting used to, but only a couple of days playing the campaign and they felt natural.
Two more notes on controls:
1. Yes, it really is tough to get the customization lab to recognize the input. This is a glitch with modern machines that I'm not sure how to fix. Just keep pressing what you want until it changes. Button combos need both buttons to be pressed at roughly the same time. Sorry I can't be of more help with this annoyance.
SAVE YOUR CONTROLS ONCE YOU'VE GOT THEM THE WAY YOU LIKE!!2. If you find your reticle won't lock or unlock when you input the correct command, press the keyboard/mouse default option in the controls customization menu, then load your saved controls again. The Keyboard/Joystick default doesn't permit this control option.
MechsStrider - Best profile and speed for smaller mech that still has torso twist.
Shadowcat - More lenient in fittings thanks to clanner Endo Steel/XL Engine, and 5 more tons. Crusty old players like me know this as the "Scat", so pardon if I abbreviate it as such on reflex :V
Bushwacker - Middle of the road mech. I don't swear by it, but I knew many who did to good effect.
Champion/Vulture - The Champ's got a considerably better profile. The Vulture only gets used for the better critical space.
Avatar/Thor - The Avatar has an absolutely amazing profile for its size, making it the premier choice. Thor isn't exactly awful though, and can be used for those ever present extra criticals off of Endo Steel.
Madcat - Much better turn speed than the smelly Orion.
Sunder - The go to Assault Mech. Phenomenal turn rate for an Assault. Profile ain't too shabby either. The Supernova is an absolute garbage mech.
Annihilator/Daishi - Take a wild guess. Anni = profile, Daishi = Crits.
Firefly/Owens/Puma - I'm mentioning these last since they are the most complex. The Firefly is technically the fastest, but it may be too difficult to achieve that speed while still mounting an effective offense. The Puma has a phenomenal profile which can easily make it the top choice. The Owens is an oddity. Due to the way its legs flank its torso, it can be almost impossible to hit the torso at all under laggy conditions. I recall pilots who'd strip off all of their torso armor, rendering the mech well armed and very fast - faster than the Firefly. That said, it probably isn't that hard to hit the torso under minimal lag. So... yeah, probably the Puma.
Stock Mechs of choiceThor B - Jump Jets plus LRMs for a scary combo. It can rain knockdown hell on its enemies, but only for 6 shots. The LRMs can be avoided by a 90 degree walk by most mechs, so fire judiciously. Works best in pairs.
Madcat D - Possesses the highly accurate streak srms, with lots of ammo.
Vulture A - 6 SRM 6s. Runs hot, but it hurts big time if you can get in range.
Shadow Cat B - Really hot running mech that works akin to Thor B, but with much more speed. Can avoid the LRM storm pretty well.
Madcat Primary - Twinned LRM 20s with decent ammo, and lots of other weapon backup. Not my first choice, but the merit can't be denied.
Weapons of ChoiceER Meds - A nice bread n butter weapon that can be counted on. Great range, good damage, and easy to fit. Work your way up from 5. I tend towards these myself. Chances are you'll want at least 15 heatsinks, and probably more. Good for light mechs, and sometimes as a backup weapon for big stuff.
ER Smalls - About 25% more damage per ton than Meds, but hotter, shorter ranged, and consumes more criticals. You'll probably use twice as much of these as meds. Best for small mechs (short range).
Flamers - Pump a couple blasts of these into someone, and they're done. The catch is that they're short ranged and have a pretty slow travel time. Great for killing fat stuff fast, but the little buggers are much trickier to hit. Unless you are fighting on a waterless desert, you'll probably need 13 or 14 to be effective all the time. Small mechs only, usually.
LRMs - Big damage, big range, and big knock down power. Expect Avatars, Madcats, and Sunders loaded with dozens and dozens of these (like 80 or more in two groups). But even 40 is pretty dangerous to be hit by. Turn rate is awful, but still puts pressure on a distant opponent. Firing beneath 90 meters strips away most of the damage, but leaves all of the knockdown power. Shooting at the ground beside a mech also retains all of the knockdown power, and can be used to knock down a light mech ankle biter to great effect. For distance opponents, firing half of them first, then the other half when the opponent is airborne or landing can catch them off guard. Mid to big mechs are best, LRM Shadowcat is decent.
LRM 5 = Less weight
LRM 10 = Less critical space
LRM 20 = Less heat (or less heatsinks!)
LRM 15 = average of all
Don't forget: clan stuff only! It's easy to accidently put on Innersphere LRMs by mistake, especially since the sorting is really wierd.
Streak SRMs - Mega awesome turn rate. These are the light mech killers, and the best anti-lag weapon in the game. Try using the unlocked reticle or freelook arm movement to pull off some crazy curved shots. Mechs can fire them upward to have them crash down on the enemy behind them, or fire them to the side to loop them around and nail an unsuspecting opponent in the back. Only the 4 model of Streak SRM should be used, as it is the best at everything. Also, don't confuse the Streak SRMs with vanilla SRMs, they don't have anywhere near as much turn rate. Best on mid to big mechs, but SSRM Shadowcat is fine.
Ultra Autocannon 20s - Twinned UAC 20s are awesome. If you get hit by them, you're probably gonna hit the dirt. If that happens, you could easily get killed unless someone intervenes quickly. Note that only the first bullet counts (you'll only see one bullet if an opponent fires these). Still, the fire rate is very high and heat is relatively low, allowing you to retry your luck very rapidly. Generally only fittable on 70 tonners and up.
Machine Guns - Yes, if you can get a bunch together, you can rip anyone open that you can get a bead on in seconds. They're kinda like flamers that don't make heat, but need ammo, and are about as awkward to use. I personally don't like these due to the ammo issues, and prefer flamers for a close range punch. Shadowcat is likely the best bet, max out that ammo!
Weapons that are meh, and whyER Large Laser - Awful damage per ton and per heat point.
ER PPC - See ER Large
Guass - See ER Large. Yeah, you can cram 4 on a Sunder for decent effect, but other stuff is better.
"vanilla" Lasers - Outdated spheroid technology. Damage is much less than clan ER lasers.
Pulse Lasers - Perpetually behind ER lasers in damage, even when heat is taken into account.
"vanilla" Autocannons, LBX Autocannons - They have a lower rate of fire. Better to shoot fast for a better chance of the deadly knockdown.
2 and 5 caliber Autocannons - Little knockdown or damage. The superior range is not worth anything here.
EquipmentMASC - Basically a supercharger for your engine. When turned on, adds a sizable chunk of speed to your mech, as well as a bit of heat.
Artemis IV - This here doohickey boosts the lock speed of your missiles and adds a limited "terrain avoidance" effect to missiles. If you're having trouble locking onto an annoying fast mech (possibly due to ECM), add a couple of these. The more you install, the better.
Artemis IV's must be installed in the same location as the missile launchers to work. Doesn't seem to boost accuracy. Probably averages the effect between affected and non-affected launchers.
ECM - This versatile piece of equipment increases the time it takes for missiles to lock on to you, nullifies NARC beacons that hit you, and mucks up the Targeting Computer by making the circle jiggle a bit. Invaluable in missile games.
BAP - Detects shutdown mechs. And that's it... it's completely worthless in multiplayer.
TAG - A spotting laser that summons missiles. The missiles arrive so slow, it's not really worth it. To its credit, you can hit guys repairing in the MFB, but you can manage that with regular weapons.
Targeting Computer - Gives you a lead circle to aim for. I generally think you should learn to manage without this, and ECM is going to mess it up an awful lot anyway.
CASE - I have absolutely no clue what this does. Yeah, it's
supposed to vent ammo explosions with no damage to you, but you don't take any damage from ammo explosions even without this thing!
C3 Master/Slave - These two items are supposed to allow sharing of radar data and effects of electronics, but doesn't do squat. Radar always has a 50km range in this game, and BAP sucks anyway. The whole "radar warfare" aspect was never properly implemented in Mech3.
Customization and Heat Management next? I should probably say words about the various glitches as well.