Xorns have a moderately powerful attack that can be dangerous to weaker characters, especially because it is very difficult to prevent them from ganging up on you. However, they respect Elbereth and have speed 9 so are usually easy to outrun if necessary. Further, xorns are rarely randomly generated and typically will not be encountered until the Castle.
The xorn is the only member of the X xorn monster class.
Xorns can be created in inaccessible areas, such as outside the Sokoban walls. This is bug C343-151.
Due to their unusual abilities, xorns are one of the most useful monsters to polymorph into. Some applications:
- Eating jewelry for intrinsics
- Phasing across difficult-to-navigate levels such as Asmodeus' Lair or the Stronghold of the Master Assassin (note that you cannot phase across the boundary between the two parts of Moloch's Sanctum, or anywhere on the Astral Plane)
- Going directly to the wand of wishing in the Castle during a speedrun or with a weak character
Warning: When morphing into a xorn any worn armor or cloaks will likely be destroyed, so remove these items before making the transformation.
When you return to your normal form and are in open space, you will be stuck in a pit that doesn't exist; this is bug C343-17. If you return to normal form while phasing through a wall that's adjacent to open space, you will be able to move into the open space. However, if you return to normal form while phasing through the middle of solid stone with no adjacent space, you will be unable to move; you can teleport out, pray (being stuck in a wall while non-phasing is a major problem), or polymorph yourself into a xorn (or earth elemental) again.
Xorns are considered kebabable (able to be skewered), and you receive a +2 to-hit bonus when using a weapon that uses the spear or javelin skills. Xorns are also susceptible to digging attacks, and again you receive a +2 to-hit bonus when using pick-axes or dwarvish mattocks. These bonuses are very rarely useful, as by the time you are fighting xorns you do not normally have trouble hitting things, and +2 is not a large bonus anyway.
Monster xorns cannot cross the water in the castle level (although polymorphed heroes can). It is often enough to lure them across the drawbridge and raise it behind you. Xorns cannot be destroyed by the drawbridge under normal circumstances (they'll just phase through it), but if there are two phasing monsters on the drawbridge, one on the portcullis square and one on the moat square, one of them will be killed if the drawbridge is raised.
A distant cousin of the earth elemental, the xorn has the
ability to shift the cells of its body around in such a way
that it becomes porous to inert material. This gives it the
ability to pass through any obstacle that might be between it
and its next meal.