Brogue Wiki
Few creatures can withstand the crushing blow of this towering mass of lead and steel, but only the strongest of adventurers can effectively wield it. Because of its heft, it takes two turns when it hits.
War hammer

A mighty weapon indeed.

The War Hammer is a melee weapon. It is a heavier version of the mace, requiring 20 strength to wield without penalty. While a miss with the war hammer only uses one turn like most other weapons, a successful attack has an additional 1 turn cooldown before the player can act again, requiring two turns per hit. Like all weapons, it must be equipped before it can be used. An ordinary (neither cursed nor enchanted) war hammer will produce 25-35 damage each successful attack (avg 30 or 15/turn).

It has the highest burst damage output of any weapon in the game and becomes particularly devastating when combined with a ring of stealth. Such a combination, properly enchanted, will often allow the Rogue an opportunity to kill even the most powerful enemies instantly. For combat against aware mobs, though, the war hammer is outclassed by the broadsword, and roughly on par in single target damage with the war axe.

As of the latest version of Brogue (1.7.5), maces and war hammers launch the victim backwards one square upon connecting (as long as there is not a wall or statue directly behind them), even without a force runic which mitigates the cooldown of a mace hit in a one-on-one fight and also allows it to be used to knock enemies into chasms, traps, or lava (though note that knocking a monster into a trap will probably result in you getting caught in the trap's effect as well), as well as freeing the player from a seizing monster; however, this can backfire against enemies with a spear, whip, or rapier-style attack, all of which can still hit you from two spaces away while you will have to close in or switch weapons once you can move again, allowing them to get some free hits in, and the turn of inactivity can still be dangerous if you are fighting multiple opponents.

Swords: Dagger · Sword · Broadsword — Axes: Axe · War Axe

Polearms: Spear · War Pike — Maces: Mace · War Hammer
Misc: Rapier · Whip · Flail
Ranged: Darts · Incendiary Darts · Javelins