Ladders are prevalent in certain stages in Super Smash Bros. Brawl. Characters are able to use ladders to quickly move vertically without jumping.
When next to a ladder's base, pressing up on the Control Stick will cause the character to grab onto the ladder (The same happens if standing at the top of the ladder and pressing down). While on a ladder, characters are considered to be in the air, so they are immune to sleep and other such effects. Characters can climb up or slide down ladders by moving the Control Stick up or down; all characters have the same speed on ladders. Multiple characters can occupy the same space on a ladder.
To release the ladder, a character can either reach its end (and dismount) or tap sideways.
Characters can grab ladders when passing by one in the air, even while helpless. This is done by pressing up or down; the character will grab the ladder and start climbing/descending. Ladders cause characters to regain all their jumps.
While on a ladder, characters cannot do anything other than climb, descend, or let go. This makes them somewhat easy to attack.
In Super Smash Bros. Ultimate, fighters are able to attack while holding a ladder.