BXR

Melee Fire, also known as BXR, is a button combo present in Halo 2. The move allows players to melee and then instantly fire their weapon, and it is performed by pressing B+X+R. Alternatively, B+Y+Y+R can be used.

Description
This move is most often used in Team Hardcore by those experienced with the Battle Rifle, where it becomes an immensely effective combat type, for the strike will first take down shields before shooting, and if aimed right can provide an instant kill.

The attack works by first meleeing. Once the melee hits the opponent and does damage, the attacker cancels the remainder of the melee animation (and the delay after the melee) by pressing X. The attacker can then instantaneously open fire, without waiting for the now-canceled melee delay to elapse. The trick only works with a full magazine, however, as pressing X with a partially empty magazine will cause the player to reload, preventing them from opening fire at all; the exception is when players do not have any spare magazines remaining, in which case they cannot reload. The exception also allows players to chain BXR.

If a player has a partially empty magazine, they can press Y twice instead of pressing X once. Pressing Y switches weapons and cancels melee animations; pressing it twice switches from and then back to the current weapon. However this method will take slightly longer to do, which can be critical in battle situations.

Strangely enough, you will automatically get a full magazine some time after a BXR, even if you shoot. This may be the result of some odd error that delays the reload (X) action.

The trick also works with the Sniper Rifle, but preferably press X before the melee hits so you are still moving towards your opponent and can get a clean snipe.

In Halo 3
Like many other button combinations, Bungie worked hard to prevent the Melee Fire from appearing in Halo 3. However, a similar combo can be used by pressing RT and B in rapid succession. By pressing RT before B, a shot is fired immediately before meleeing. It works best with single-shot weapons such as the Sniper Rifle, enabling a very fast kill. While attempting to use this trick with a Battle Rifle, if done incorrectly, the rifle will only fire 1 or 2 shots. Most players, though, have adopted the B+A+R. This allows a player to melee, jump backwards and shoot a target while in midair.

R+R+Y+B
In Halo 2, and when playing Halo 3 offline, an additional button combo becomes available: RT+RT+Y+B. This performs a shot followed by a melee and a second shot that, when executed correctly, fires at the unshielded head of the target. This results in a kill within the timespan of a melee. This is, however, only confirmed to work with the Battle Rifle.