The plot is fairly light. A group of adventurers (initially a Wizard, a Ranger, a Warlock, a Paladin; a Thief and a Priest were added via updates) have just finished exploring the titular ruined Castle Hammerwatch and are about to exit, when the bridge suddenly collapses, cutting off one (or more) of the party from the others. The stranded adventurer(s) must now fight their way through the monster and trap filled castle in order to find another escape route and rejoin their comrades. Along the way, they will fight hordes of giant beetles and poisonous worms, legions of skeletons, and, of course, Dragons.
In the September 2014 update, a brand new campaign was added, titled Temple of the Sun. It's more plot-heavy than the original campaign, with the titular group of adventurers journeying to a desert village of Sunspot, where the frost sorcerer Krilith sneaked to the Sun Altar and summoned the evil Sun Guardian Sha'Rand. While the villagers of Sunspot have sealed Sha'Rand in the Sun Altar, a weakened Krilith retreated into the deep caves to recover his strength. The party must delve into the ruins and slay both Krilith and Sha'Rand before the sorcerer can regain enough magic to free themselves.
A sequel/spinoff, Heroes of Hammerwatch, was released on March 1, 2018, and is basically the original game but with roguelite mechanics.
Provides examples of the following tropes:
- Bag of Sharing: Gold is shared amongst all party members.
- Bat Out of Hell: Bats are the weaker enemies found in the Prison.
- Chain Lightning: The Warlock's starting spell.
- Character Class System: Paladin, Ranger, Warlock, or Wizard. Take your pick.
- Recent updates added Priest and Thief to the selection
- Crate Expectations: Crates and barrels all over the place. Mostly, they contain gold.
- Poison Mushroom: But some contain bombs; normal bombs that deal a lot of damage and mana bombs that take off MP.
- Dash Attack: The Paladin's starting skill.
- Dem Bones: Skeletons make up a majority of the enemies faced in the Armory.
- Dungeon Shop
- Heroes Prefer Swords: The Paladin.
- The Medic: The Paladin can get a healing spell later on. The Priest starts with one.
- Mook Maker: Most enemy types have some sort of spawner.
- Multi Shot: The more powerful skeletal archers in the Armory.
- One-Hit-Point Wonder: There is an optional challenge that turns you into this.
- Poisoned Weapons: The Warlock has a poisoned dagger.
- Stationary Boss: The Queen, the boss of the Prison.
- 1-Up: Golden ankhs provide extra lives, which are shared amongst the party.