Scumming

Scumming (sometimes level scumming) is a technique wherein players repeatedly restart the game until the conditions are in their favor. It's a common tactic in roguelikes that procedurally generate levels; games that generate new levels whenever the player descends a staircase are especially vulnerable, as the player can simply walk up and down the same staircase until they like what they see. As Spelunky doesn't permit players to return to previous levels, this is a non-issue, but certain kinds of scumming are still possible:

• Shop scumming: The player restarts the game until a shop is nearby. The shop can then be robbed, allowing the player to start out with a collection of useful equipment (or at least a shotgun).
• Darkness scumming: The player restarts the game if the "I can't see a thing!" level feeling occurs. This is one of the least desirable level feelings to get, as the reduced visibility makes it very easy to take damage from hidden enemies, traps, and falls.
• Shotgun scumming: The player restarts until the Restless Dead level occurs, then tries to find and bomb an "Ash" tombstone in hopes of receiving a shotgun. Note that "Ash" tombstones are generated infrequently enough to render this technique almost worthless.
• Jetpack scumming: The player restarts until the "psychic presence" level feeling occurs, then kills the Alien Boss and takes the jetpack.

Because Level 1 never has shops or level feelings, a player who intends to scum will generally want to make use of tunnels to start on other levels.