To successfully complete the level, the player must assign specific skills to certain lemmings. Which skills and how many uses of each are available to the player varies from level to level, and the player must assign the skills carefully to successfully guide the lemmings. There are eight skills that can be assigned: Climbers climb vertically though fall down if they hit an overhang. Floaters use a parachute to fall safely from heights. Bombers explode after a five-second timer, destroying themselves and any destructible landscape in close proximity, though not damaging other lemmings or traps. Blockers stand still and prevent other lemmings from passing; lemmings that hit a Blocker simply reverse direction. Builders build a stairway of 12 steps. Bashers, Miners and Diggers dig horizontally, diagonally downwards or directly downwards respectively.