Super Mario Bros. 3 (NES)
In World 8-Battleships (the second stage in World 8), Mario can safely swim in the lava. With enough practice, you can have Mario swim underneath all the ships until the end of the level.
Find hidden Blocks
In stages with the starry background, you can tell where the hidden Blocks are because the stars are a different color.
In the grassy levels, there are tunnels underneath the ground that Mario can travel through if he can fly. Using a P-Wing, Mario can fly under almost the entire level! Try this trick in Worlds 1-2, 3-4, and 6-8.
If you get three Star cards in a row from the Card Roulette at the end of normal levels, you'll get a 5-Up bonus. Here is a trick to get a Star every time: Run by holding B, and jump at a 45° angle at the Card Roulette.
99 1-Ups: World 1-2
Make sure you are Raccoon Mario, or at least Super Mario, when you start this level. Get the Super Leaf from the first Question Block, then jump over the next pipe. Wait a few seconds for a couple of Goombas to come out, then press A to jump on one, but keep holding A and you'll bounce higher. Float down slowly with your tail and land on another Goomba without touching the ground. Do this about six more times, and as long as you don't touch the ground, any enemy you stomp after that will give you a 1-Up.
99 1-Ups: World 2-Fortress
Use Raccoon Mario, and the technique used in the trick above, to get 1-Ups from the group of three Dry Bones found at the start of the level. When you bounce off, make sure you stay in the air long enough to allow enough time for the Dry Bones to regenerate so you can stomp them again.
99 1-Ups: World 3-9
Kick a Koopa shell between the second and third Bullet Bill cannons for points and eventually 1-Ups. Kicking a Koopa shell between the third cannon and the pipe also works, but is slower.
Chain Chomps can break free if you hang around too long. After 47 lunges, their chains will flash. On their 50th lunge, they will finally break away from the block, aiming for Mario as they fall off-screen.
"I'll trade you for that wand..."
You'll get a different thank-you message from the king if you beat a Koopa Kid with the Frog Suit, Tanooki Suit, or Hammer Suit. The king has something different to say for each of the three suits.
The lower half of Bowser won't damage Mario. Thus, small Mario can walk through Bowser while he's on the ground. Also, small Mario (and Super Mario in ducking position) won't be hurt by Bowser's stomp attack as long as they stay on the ground.
Whistle while you warp
Using a Warp Whistle anywhere in the Warp Zone will take you to World 8. Thus, the quickest way to World 8 is to get the whistles from Worlds 1-3 and 1-Fortress, use one, then warp again while in the Warp Zone. However, you may want to play through a few more worlds to stock up on items and extra lives before starting the grueling journey through World 8.
On the World 3 map screen, the "bonus area" contains two islands that you can reach with the canoe. One of them is shaped like a mushroom. Also in World 3, the island with the Castle is shaped like Japan.
On the World 7 map screen, you trek across three pipe-shaped islands.
The designers must've been totally excited about Super Mario Bros. 3, because there are four "3's" hidden throughout the game.
White Mushroom Houses
In certain stages, collecting enough coins will make a White Mushroom House appear on the Map Screen. Inside, Toad will either give you a P-Wing or an Anchor, depending on the World number.
*There is no White Mushroom House in World 8.
In Worlds 1, 3, 5, and 6, you can turn a Wandering Hammer Brother on the map screen into a lucrative Treasure Ship. Here's what you have to do:
Of course, you get 50 points per second remaining after you hit the Roulette Block, which affects the all-important tens digit of your score, so you'll have do a little planning ahead. Keep in mind that if you stop the timer on an even number, your tens digit won't change. If you stop the timer on an odd number, your tens digit will increase by 5. So, if you're at the Roulette Block with 66 Coins and a score ending in -60, you'll want to stop on an even number. If you have 88 Coins and a score ending in -30, you'll want to stop the timer on an odd number.
The Treasure Ship contains 169 Coins and a hidden 1-Up Mushroom just before the end pipe.
N-Spade game solutions
N-Cards will appear on the map screen every 80,000 points you earn. Touch it, and you'll get to try a card-matching memory game. If you match a Super Mushroom, Fire Flower, or Starman, it will be put in your item inventory. 1-Up, 10- and 20-Coin cards are added to your totals immediately.
Here are the 8 different N-Spade board patterns used:
Hammer Bros. "bonus spots"
The wandering Hammer Bros. in Worlds 1, 3, 5, and 6 will have items hidden among their brick platforms only when you fight the Hammer Bros. on certain spots on the map screen. These "bonus spots" are marked on the maps below.
Click the red Hammer Bro. icons to see maps of their stages and item locations.
The spot in World 5 (sky) is interesting because it has three items: a 1-Up, a multi-coin block, and a power-up. Since it is so far away from the Hammer Bro.'s starting point, we still haven't seen him stop there...