Battlefield 3 does a great job on informing the player of things they need to know. Even the most basic stuff, such as how different attachments effect weapon performance and quick tool tips for vehicles and kits, are all right in the manual. But, like any media where there's a lot of people with way too much time on their hands, a lot of neat things will be discovered along the way. Whether or not these things were intentional on part of the developers, we may never know. But, none the less, I think it my duty to share this information.
I'm not going to bullshit you with obvious stuff, like "give heath" and "share ammo" and "use motion sensors." You all know this stuff. I'm going to give you some rather obscure information that you may already know, or were totally oblivious to. If at any point you say "I didn't know that," then I've succeeded. Please comment if I do mention something you didn't know.
By the by, if there's anything you know that you think is worth mentioning, please add it in the comments. I'll be happy to research it and give credit.
UPDATE: according to the upcoming patch notes, some of the information here will become outdated. I will cross that information out when the patch comes. UPDATED: Information that is now wrong is slashed out. UPDATED: Again for Aftermath. Not all information is perfect yet. UPDATED: A very late but most likely final update.
- Reviving a player in Team Deathmatch or Squad Deathmatch will subtract the kill away from the enemy team.
- Respawn Tickets are subtracted for every spawn in Conquest, unlike for every kill in Rush. Therefore, if the match is drawing to a close and tickets are tight, it's in your team's best interest to not spawn in.
- In Rush, the attackers can continue the game with zero tickets as long as at least one M-Com is armed. However, if the M-Com is disarmed, or the other M-Com is not armed when the first is destroyed, the round will end.
- In Scavenger mode and Gun Master, your choice of class has no impact on game-play beyond appearance all that implies. Points earned in combat do not go towards any class nor does any class specific assignment gain progress. Weapon specific assignments, however, still gain progress.
On the Ground
- Engineers carrying their Repair Tool can pick up enemy explosives such as AT Mines and C4 by using the interact button. The EOD Bot does the same.
- Health kits and ammo crates from the opposing team will not be highlighted on the HUD or map, but will still heal you and provide you with ammo.
- Health kits and ammo crates can be destroyed by shooting them. This goes for your own, friendlies, and enemies.
- Ammo crates and health kits will persist indefinably unless destroyed or deployed elsewhere.
- Ammo crates and health kits become anchored to whatever they're deployed on, and will not be knocked away by nearby explosions. You can take advantage of this fact by placing ammo or health on vehicles.
- If the falling debris from a destroyed building do not shake the screen and make loud crunching sounds when impacting the ground, it will not kill people.
- Attaching your 40mm Grenade Launcher to your rifle using the Underslung Rail makes it quicker to access than if you carry it separately.
- Assaults carrying health kits will have one on their back. Same goes for Engineers with Repair Tools. Mines also appear on Engineers backs.
- While parachuting, pulling back on your movement stick (or whatever controls) will slow your decent and reduce the distance you travel. Pushing forward will speed up your decent, but can also cause you to land short of your intended target. Hitting the ground while pushing forward to speed up can cause injuries.
- Mounted TOW launchers have no explosive element, and therefore have no splash damage. This makes them completely useless against infantry.
- Your sidearm's performance is not effected when under suppressive fire.
- The 870 Combat has a tighter spread for pellets compared to the other shotguns. It also has higher close range damage for slugs.
- The AN-94 has the least recoil of all weapons when used in 2-shot burst mode.
- High powered bullets from magnum revolvers, shotgun slugs, frag shells, or sniper rifle rounds can detonate explosives such as AT Mines and C4 by shooting them.
- High powered scopes of the 6x or 7x level do not produce a visible glint when mounted weapons other than sniper rifles.
- Claymores will not detonate if you crouch or crawl.
- The MAV's projectile jammer can destroy other gadgets, including other MAVs, EOD bots, spawn beacons, SOFLAMs, and even claymores. It can not, however, destroy C4 or Mines.
- Mines will anchor to vehicles. This can be used to make a VBED or booby-trap vehicles.
- Laser guided Javelins do not require line-of-sight to lock on or fire, but still require a clear firing lane for the missile to approach the target and hit it.
- It is impossible to preform a knife takedown on someone operating a mortar, but it is possible to slash them across the face if you stand in front of them.
- The XBOW is totally silent.
- The XBOW standard bolts do up to 100 damage and can therefore guarantee a kill up to 20 meters if the bolt lands in the trunk or head. BA Bolts move faster and have less drop but their maximum damage is only 80.
- XBOW high explosive bolts do 200 damage in splash damage but only up to half of a meter. Hitting the ground directly below a standing enemy will only do 25 damage. The explosive bolts' effectiveness is also related to point of impact on a vehicle; for best results, a perpendicular hit directly to the rear is nessesary.
- Scan Bolts act like a T-UGS for a split second by revealing enemy movement near their point of impact. The sound of a Scan Bolt impacting makes a distinct sound of several beeps in very quick succession.
- Reactive Armor can be repaired.
- The IR Smoke screen only works if you keep your vehicle inside the cloud.
- The AMTRAC has IR Smoke by default. It also has reactive armor on both sides and the front, but the rear it unprotected.
- Standard shells and the APFSDS-T Shells from IFVs ignore reactive armor. MBT shells, portable RPGs, mounted TOWs, Vehicle TOWs, are all absorbed by reactive armor plates.
- A TOW will destroy an armored vehicle with one hit directly in the rear.
- Damage done to reactive armor plates that do not damage the vehicle in any way will not give damage feedback (such as the metal crash sound, blur, or damage indicators) to the vehicle crew, but will still give hitmarkers to the player attacking.
- Reactive armor can absorb explosive damage from C4 and mines. If C4 sticks to the top of the vehicle, the reactive armor will not absorb the damage nearly as effectively.
- The Cannon HE for the Tank Destroyer has less recoil compared to the anti-armor shell. It has less of an impact damage is exchange for a greater explosive element, making it ideal for anti infantry use.
In the Air
- Transport helicopters have IR Flares by default. Transport helicopters also have stronger armor compared to scout or attack choppers.
- IR flares will spook off incoming missiles but will not break targeting lock from your attacker.
- Guided Missiles from jets can lock on to air vehicles if they are laser designated.
- ECM Jammers will prevent a lock from occurring,
but will not spook off missiles already in flight. ECMs can now spook off an incoming missile, but only if the missile flies through the chaff cloud. The ECM's performance as far as spooking off incoming missiles is inconsistent, and should not be relied on exclusively.ECM will not spook off a missile, but will cause its targeting system to spaz out, making the missile turn around constantly. Being low to the ground when deploying ECM, generally from a helicopter, can cause incoming missiles to miss and hit the ground.
- ECM will hide your air vehicle from players using Air Radar temporarily when activated.
Nothing can spook a laser guided missile once it's in flight. You must out-run it or evade it.IR flares can spook off a laser guided missile but if laser designation is maintained the missile will still hit. Dump flares and get evasive to doge a laser guided weapon.
- Flying Below Radar will prevent Air-to-Air lock, but will not affect man portable Surface-to-Air weapons of the Stinger or IGLA variety.
- Laser guided weapons from vehicles, as well as the Javelin, have a finite distance they can fly. It is possible to evade them by flying away from the missile source at top speed.
- If a guided weapon misses, such as when attempting to hit a very fast moving air unit, it will attempt to turn. The turn radius of the projectile is limited, and being very low to the ground can cause the missile to impact the ground.