The polyself bug is a fairly serious flaw in the handling of a self-polymorph by an experience level one character. It is listed as SC343-10: SC343-10: Player can raise HP and Pw by dancing with vampires. In order to exploit this bug, a player would need to drain life themselves to reach experience level one, whether by the spell, by throwing a level-draining weapon upwards, by the attack of a level-draining monster, such as a wraith or vampire (as alluded to in the official description of the bug), by praying repeatedly, or by using any other method of level loss.