- 5 + 0.5×XL AC
- Unarmed Combat base damage set to 5 and uses XL instead of Unarmed Combat skill
- Movement delay reduced to 8 auts
- Non-living holiness (Torment immunity)
- Insubstantial (rSticky, rPetrify, immune to constriction, Shatter, Grasping Roots, Leda's Liquefaction)
- Good stealth bonus (same as Spider Form)
- Tiny size (like Spider Form), with an appropriate increase in EV
- Permanent flight
- You can't use weapons, armour, or jewellery.
- You can't cast spells.
- Randomly blinks from time to time (10% chance each turn).
- Sometimes moves as if confused, although won't bump into walls or into allies (10% chance each turn)
- Prior to 0.22, wisp form, and most other bad forms disallowed the use of wands.
- Prior to 0.15, wisp form allowed the player to blink as an ability, but prevented you from reading scrolls. It also granted perfect conservation, protecting your consumables from item destruction.
- Wisp Form was added in 0.12.