A guide to completing the first World 3 Fortress in Super Mario Bros 3 for the Nintendo Entertainment System.

How to Clear the Fortress

Go to the right, and you will see a Roto-Disc spinning around. Don't let it hit you. There is also a Dry Bones here. To the right, there is another Roto-Disc.

To the right, there is a pipe, then a Thwomp. After that, there is a hallway with Dry Bones, Thwomps, Boo Ghosts, and a total of 9 doors. Most of the doors lead to a watery area with Green Cheep-Cheeps and some ? blocks that have Super Mushrooms or Super Leaves in them. If you went through an incorrect door and ended up in the water, just look for a pipe and go up it. You'll be returned to the pipe to the left of the Thwomp.

If you want a 1UP Mushroom, go through the fifth door (it's in the middle of a group of four columns).

If you want some coins, go all the way to the right side of the hallway and go through the final door. If you try to jump up through the gaps in the platform above you, they all turn into bricks with a coin in them. To get to the coins above, you need to stand in front of the door and jump straight up to reveal a block, then stand on the right edge of that block and jump up to reveal another block. Then you can get the coins in the platform. When you're done, go back through the door.

To reach the boss of this fortress, go through the sixth door (it's to the right of a group of four columns). From there, you can go up the stairs on the left and go through the door. You'll reach the boss's room.

Boom Boom

Go to the right and you find the fortress boss, Boom Boom. He 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. After you stomp him the first time, he will start flying in the air, going left and right, then he sometimes stops and tries to swoop down at you. Try to stomp him when he swoops down. 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

Don't use the Hammer on the boulder next to the Spade House (the Hammer is from the first Hammer Bro on the map). Save the Hammer for later.

If you can reach the second Hammer Bro, you can defeat them (two Hammer Brothers) to get a Starman.

The locked door will disappear, giving you access to a Warp Pipe, but the pipe just leads back to the spot to the right of the START tile, so there's no need to go there. The second Warp Pipe just leads to a dead end at the moment, so ignore that one as well.

You can optionally visit the Spade House. When you're ready to move on, you can visit World 3-4 or World 3-5 (which is almost entirely underwater, making it a good choice for the Frog Suit... or you might want to use a P Wing to fly over the water, which also allows you to hit the bricks on top of the wooden blocks to get some coins).