In most variants of the computer game Angband, players may choose to play with preserve on, or off, at the creation of each character. When it is on, artifacts are not permanently lost if they are in a level that the player leaves, but a special level feeling never occurs - making it harder to find levels with an artifact on the floor. Many characters have died because the player was afraid to leave a special level, and encountered something like a graveyard or other very challenging collection of monsters - which also have an (often high) chance of causing a special feeling.
The level feeling is always increased significantly when an artifact is present, even if playing without preserve mode. The player may or may not draw the correct conclusion about the reason for the level feeling, however.