A guide to completing the second fortress of World 7 in Super Mario Bros 3 for the Nintendo Entertainment System.

How to Clear World 7's Second Fortress

Go to the right and make a running jump from the top of the ledge to land on the pipe when the Piranha Plant goes down, then jump to the second pipe. Carefully avoid the Boo ghost and jump onto the orb while avoiding the Roto-Disc.

Jump onto the next pipe after the Piranha Plant goes down, then fall down from the right side of the pipe and hit the brick to get a Starman. If you miss it, just follow it to the area after the Venus Fire Trap's pipe. Otherwise, jump back up on the brick and then jump to the right from pipe to pipe. After the Thwomp, there is a Piranha Plant in a pipe, a non-lava floor, an empty pipe, and a Boo ghost. After that, there are two Piranha Plants in the set of five pipes.

Next, there are three pipes close together, and the middle ones have Piranha Plants going up and down. After you get past them, there is a Venus Fire Trap in a pipe, followed by a Piranha Plant in a pipe with a ? Block over it that contains a Super Mushroom or Super Leaf.

Make a running jump to the right to land on the next pipe, then wait for the Thwomp to go back up before you jump on the next pipe. Then make a running jump to reach the pipe after that.

Next, there is a pipe after some lava, and there are two Boo ghosts nearby. Get past them and jump onto the ledge on the right, then fall down to the pipe beneath the ledge when the Piranha Plant goes down. Go down the pipe.

Go to the right and let the Dry Bones go past, then if you're tall, run and crouch to get through the gap when the Roto-Disc is not in the way.

Then go to the right to make the Thwomp come down, and when it's going back up, run and crouch to get through the gap when the Roto-Disc is not in the way.

Then go up the stairs and go to the right to reach the fortress boss.

Boom Boom

Boom Boom will move left and right, and sometimes he will crouch and slide. Whenever he crouches, his spiky shell is not safe to stomp on. Try to stomp on him when he is running around. You can also hit him with fireballs if you're Fire Mario. After you stomp him the first time, he will sometimes suddenly stop, then jump high up. It can be difficult to aim your jumps correctly when he stops and jumps, so watch him closely. After you stomp on him a second time, he will very quickly run left and right, so jump carefully to avoid letting him bump into you.

After you stomp him a third time, he is defeated, and drops a Magic Ball. Collect it and you will complete the level.

After the Level

The locked door will disappear, giving you a shortcut to an earlier part of the world. Continue on to World 7 Piranha Plant 2.