Button combo

"Button Combo" is a colloquial term that refers to a series of button combinations for Halo 2 that allow for special tricks.

Introduction
These button combos utilize disruptions of firing and reloading animations, and successful executions lead to special advantageous effects like automatic Plasma Grenade sticks, instant close-range kills, etc...These are often favored by professional players.

However, Bungie has declared these combos all as cheating, and many players disapprove of such "cheap" exploitations.
 * by the letter of the law, button glitching is cheating, and we suggest people to report it via feedback. -- Tom Gioconda

One Touch Tricks
The following is an explanation of how single buttons can be incorporated in button combos. For more information on their normal usage, see Halo Controls.

X - The X button will of course reload a weapon, but besides that it can cancel the timers of animations such as melee or grenades (off-host) enabling you to fire or melee sooner than you would normally. Y - The Y button will of course switch a weapon which directly after you can throw a new melee (or sword lunge), but besides that it can also cancel reloading, cancel melee animations and when used in a quick double sequence it can enable you to open fire again sooner after reloading or cancel reloading if you are caught off-guard while reloading. B - The B button will let you melee, but when used at certain times it can do more, after reloading, for example you can cancel the reload timer by melee-ing and after that pressing X. The melees lunge can also be used to swing at your opponent, after which you can snipe someone no-scoped or stick people with a plasma grenade. R - The only function the R button has is to shoot, but as you will read below, in combination with other buttons a lot of tricks can be achieved. L - Besides getting grenades out, you can actually use it to reload. After you have thrown a grenade and press X you will automatically reload, even though you can keep shooting (off-host). Overheat - Overheated plasma weapons have extra abilities. After a weapon overheats, it will reset the timers for shooting, melee-ing and nading, this can be used to get quick sessions of double grenades.

Button Combos in Halo 3
Though Bungie attempted to excise button combos from Halo 3, as they were never intented to exist within the game, some players had discovered a "BXB-style glitch" that allowed them to melee twice in quick succession.

Bungie quickly discovered this glitch and posted on the February 8, 2008 weekly update that they had excised it from the game and it would be fully removed once the first auto-update takes effect in mid to late February, 2008