Explosion

Many attacks create explosions which cause damage in a radius around the point of impact.

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Damage from explosions drops off by a factor of 1/N, where N is 1 point blank and adjacent and increased by 1 per 2 steps distant, so it first decreases at 3 steps distance.

An explosion will destroy an item if and only if damage at that square is more than 10. Unique items are never destroyed. Arch-vile blasts, since they always do more than 10 damage, always destroy items.

No explosion will pass through walls. Even the BFG 9000, with its special animation that shows it ignoring walls, is stopped by them. However, explosions expand left to right and can damage things behind walls they have already destroyed.

Secondary explosions from the BFG have no in-game effect other than to inform you of lost items. Exception: They count as any other explosion for the purposes of the recursive explosion bug.

Recursive explosions corrupt internal tracking data, causing monsters to be affected more or less than 1 time per explosion. However, it is not possible to cheat damage entirely - you must take damage at least once in total.

Some explosions, notably those from acid barrels and napalm barrels, have a chance to leave behind puddles of acid or lava. These explosions calculate damage for every tile in their radius and leave behind a puddle whenever the damage is at least 21.

No explosive missile weapon does impact damage normally.