While you're climbing, each foot of movement costs 1 extra foot (2 extra feet in [[Difficult Terrain]]). You ignore this extra cost if you have a [[Climb Speed]] and use it to climb. At the DM's option, climbing a slippery surface or one with few handholds might require a successful DC 15 STR (Athletics) check. If a creature gains the [[Prone]] condition while Climbing, it must repeat the STR (Athletics) check if the climb required an ability check.