Clockwork Knights, Clockwork Bishops, and Clockwork Rooks will not respawn and graves will not reset on their own, but they can respawn if they are part of the caves, as the caves can be reset. This makes Gears a renewable resource in the base game.
Downloadable Content
In the Reign of Giants DLC, Tumbleweeds have a chance to drop Gears, making them a renewable resource. The game will additionally generate more Chess biomes as well as Gears lying about on the ground, which makes them easier to find.
In the Shipwrecked DLC, Floaty Boaty Knights drop Gears, also another renewable source. These are currently the only reliable source of Gears in this DLC. Each Floaty Boaty Knight drops one to three Gears. There is also a small chance to obtain Gears if the player digs up Sandy Piles, uses the Slot Machine, or digs up X Marks the Spot chests spawned by Message in a Bottle. Gears can be used to craft the Quacken Drill and to restore the durability of the Iron Wind by 25%.
In the Hamlet DLC, clockworks guarding the Stone Thing will drop Gears. The player can also buy Gears in 'The Sty' Oddities Emporium for 10 Oincs. Large Iron Hulk will also drop Gears when killed. The last two methods are renewable sources of Gears in this DLC.
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