This is the most iconic secret in the game. It allows you to rack up dozens of 1-Ups in a single level by repeatedly bouncing on a Koopa Troopa shell.
: Let the first Koopa pass. Jump on the second Koopa so its shell stops on the edge of a step. Super Mario Bros Cheats Nes Infinite Lives
: At the very end of World 3-1, right before the flagpole, there is a stone staircase with two Koopa Troopas descending. This is the most iconic secret in the game
: Jump straight up and land on the shell. If your timing and position are correct, Mario will repeatedly bounce on the shell without touching the ground. Jump on the second Koopa so its shell
In the original for the NES, "infinite" lives aren't a menu option but an exploit built into the game's mechanics. The most famous method is the World 3-1 Turtle Trick , though you can also use Game Genie codes if you have the hardware or an emulator. The World 3-1 Turtle Trick (Turtle Tipping)