Grind Locks were small locks that could be accessed by using the Shrink Ray. Once inside a grind lock, Ratchet used grind boots to navigate a grind rail, and hit various targets along the way to disable force fields blocking the path. The objective was to get to the end of the grind rail without dying, by dodging or destroying obstacles, switching rails, and passing force fields. If completed successfully the lock would be unlocked and the door would open, Ratchet could then use the Shrink Ray to return to his normal size.
- Ratchet & Clank: Size Matters (first appearance)