Double Melee

"Double Melee" refers to three button combos present in Halo 2, all of which have the same effect: they allow a player to melee twice, with no delay between the attacks. The three combos are B+X+B, B+Y+B, and B+L+B, the last of which also works in Halo: Combat Evolved.

When a player performs the combo, they start by meleeing an opponent. As soon as the melee hits and does damage, the attacker then presses X, which cancels the rest of the melee animation and nullifies the remaining delay. (If the attacker possesses a secondary weapon, they can also press Y; switching weapons also cancels a melee animation.) The attacker can then press B again without waiting for the now-canceled melee delay to elapse.

If the player has a secondary weapon, they can Y between melees to switch and melee with your secondary, or double-tap Y to melee with their primary weapon again. This is useful if carrying an Energy Sword or Brute Shot, both of which have much stronger melee attacks than other weapons.