Impossible

NetHack generates an impossible message when something such as a monster or object reaches a state that it should not be possible to reach; it displays a short description of the problem, followed by "Program in disorder - perhaps you'd better #quit.". These messages are generated by the impossible() function in pline.c.

Some bugs in NetHack 3.4.3 generate impossible messages; for example, C343-33, "Sometimes a monster may remain hidden under a corpse that has rotted away.", can result in a player polymorphed into a hiding monster hiding under a non-existent object, generating the message "hiding under nothing?" when a monster tries to attack the polymorphed player.

If an error results in the session being unable to continue, the game will normally panic instead of issuing an impossible message.

This page may need to be updated for the current version of NetHack.

It may contain text specific to NetHack 3.4.3. Information on this page may be out of date.

Editors: After reviewing this page and making necessary edits, please change the {{nethack-343}} tag to the current version's tag or {{noversion}} as appropriate.