Acid Bolt
School Arcane, Clerical
Type Damage
Range Bolt
Base cost 15
Equivalent item wand of acid

Acid Bolt is an offensive bolt spell in ADOM. It allows the caster to fire a ray of acid in a specified direction, damaging every creature (that doesn't evade or resist) in its path.

Acid Bolt is a bolt spell, thus sharing the following features:

  • The spell travels in a straight line in one of the 8 possible directions.
  • Acid Bolt damage decreases slightly as it travels.
  • Monsters are able to shrug off the bolt completely resisting the damage.
  • Acid Bolt will disappear as soon as it hits a wall or a door.
  • Damaging monsters with a bolt spell while invisible will not betray the PC's position to them.

Acid Bolt is more expensive than the other elemental bolt spells, but usually more effective. Whilst no monsters in the game take extra damage from acid attacks, very few are immune to them — black and karmic dragons, diamond golems and greater titans being notable examples of enemies that are. Unique monsters such as Nuurag-Vaarn and Keethrax are notable for resisting all elemental attacks except acid.



Acid Bolt damage is dependent on the PC's level (L) and proficiency (P) with the spell. As mentioned above, it's slightly loses in firepower as it travels further from the caster (r stands for the amount of remaining travel points — it starts equal to the spell radius and decreases by 1 point per each tile). The exact formula for spell damage looks the following way:

{max[4, (L + P) / 3]}d9 + r


Acid Bolt radius depends on the PC's Willpower score (W) and level (L). The exact formula looks the following way:

W / 4 + L / 4 + 2


In the example situation a level 6 Wizard with 15 Willpower casts a +2 Acid Bolt directly to the east. According to the formulae above, the effective spell damage will be 4d9 + r and the spell radius will be equal to 6.


The goblin ('g') will receive 4d9 + 4 points of damage, the orc (monster) ('o') will receive 4d9 points of damage, while the rabid dog ('d') will not be affected, as the bolt will disappear right before it.


Acid Bolt also causes more item destruction than other bolts spells — with a high risk of destroying loot made of iron or weaker materials, and a small chance of destroying mithril and adamantium items. It is thus usually not the best spell to clear out vaults with, unless the possible rewards of one wouldn't outweigh the risk to the PC's life anyway.