1-Up Chambers, or 1-Up Rooms, are hidden areas that appear in Super Mario World. They are accessed through certain Warp Pipes in Donut Plains 1, Donut Plains 3, Vanilla Dome 3, #4 Ludwig's Castle, Forest of Illusion 3, Chocolate Island 5, Valley of Bowser 1, and Valley of Bowser 3. 1-Up Chambers consist of five horizontal floorboards, each with three Prize Blocks within it. If Mario or Luigi jumps onto a floorboard, he cannot return to the one below him. The topmost floorboard has a Warp Pipe leading back into the main level.
With each tier, the goal is for Mario or Luigi to jump at the Prize Blocks in a certain order, which is always randomized. If Mario or Luigi jumps at the correct first and second Prize Blocks each, he earns a coin, followed by a 1-Up Mushroom in the third Prize Block. Jumping at the first one or two Prize Blocks in the correct order turns each one into an O/X Block. If Mario or Luigi jumps at a Prize Block in the incorrect order, every Prize Block in its row turns into a Brown Block.
As Caped Mario or Caped Luigi, there is a method in which he can always hit each row's Prize Blocks in the correct order. To do so, he must perform a Spin Jump on the left side of each Prize Block from left to right.