Fistfight

Fistfight was a Halo: Reach Firefight gametype. It was featured in the Firefight Arcade playlist. It allowed players to use the Armor Ability of their choice, with a default load-out of a Energy Sword and a Gravity Hammer. Infinite ammo was enabled. If players reached the Bonus Round, the dropship released vast numbers of Skirmishers instead of Grunts; this is because the weak, slow-moving Grunts would have been even less of a threat than normal with Hammer-wielding players around, though the fast, nimble Skirmishers posed more of a challenge.

This gametype, while still usable in custom-game-firefights if saved, no longer exists in the playlists. When 343 Industries consolidated Firefight Limited, Firefight Arcade, and added a multiplayer Score Attack in the Firefight and Firefight Doubles playlists, all differing types of Arcadefight were removed except Arcadefight, and Arcadefight NEP was added.

Tactics
There's no room for subtlety here; all you get are melee weapons. Your best bet is to either dance around your enemies with the Energy Sword and try to avoid their fire until you take them all down, or charge headlong into groups of Covenant and swing your Gravity Hammer wildly. Once the Mythic skull kicks in, indirect hits from the Hammer won't kill Elites and Brutes, and while direct hits are always effective, the Hammer is very, very slow to swing. Once you reach the later stages of the match, it's probably a good idea to use the Hammer on groups of weaker enemies, like Grunts and Jackals, and to use the faster Sword to take down groups of Elites and Brutes one by one.