Amulet of Yendor

The goal in nethack is to retrieve the Amulet of Yendor and deliver it to your god. Doing so promotes you into the ranks of the demigods. However, there's always some catch, and there are quite a few here. There's a nasty Wizard of Yendor guarding the amulet, and you'll have to kill him, and he doesn't stay dead so you'll have to kill him over and over. Also, the amulet doesn't really like ascending staircases; sometimes attempting to do so with the amulet will magically take you down a bit instead.

In game terms, the actual effects and powers of possessing and/or wearing the Amulet of Yendor are as follows:

• Casting spells will drain your energy faster
• You suffer increased hunger
• Your luck timeout will be increased
• Monsters generated will depend upon the deepest Dungeon level you've reached, rather than the usual calculation of your experience level and the current dungeon level
• Monsters will be less likely to be asleep
• Level teleport will fail
• The Wizard of Yendor always knows where you are
• You gain clairvoyance, as the spell
• When you try to go upstairs in Gehennom, you might teleport down 1 to 3 floors instead (this is extremely irritating)
• When worn, you'll get messages that the amulet is getting "hotter" as you approach the portals in the endgame levels
• The Wizard of Yendor can teleport or level teleport to come kill you

As you can see, possessing the Amulet is pretty much a bad thing. Don't wear it -- wear your Amulet of Life Saving instead, 'cause you'll probably need it.

Plus, once you've gone all the way down through hell and beyond to get it, you have to climb all the way back up with the aforementioned difficulties, ascend through the elemental planes, and then you have to sacrifice the frikkin' thing on the correct altar (one in three chance). Then, at this point, you have ascended. I've never ascended. I've played this game daily for the last several years.