Improvised damage table for when a Dungeon Master needs to decide how much damage a player character will take.
D&D Core Info

Improvised Damage

Improvised damage is a way to figure out how much damage a nonstandard weapon or attack might do. This can be used for anything that deals damage but wouldn’t have a set amount applied to it in the rules or books.

Improvised Damage Examples

Dice Examples
1d10 Examples:  Burned by coals
Examples:  Hit by a falling bookcase
Examples:  Pricked by a poison needle
2d10 Examples:  Being struck by lightning
Examples:  Stumbling into a fire pit
4d10 Examples:  Hit by falling rubble in a collapsing tunnel, stumbling into a vat of acid
Examples:  Stumbling into a vat of acid
10d10 Examples:  Crushed by compacting walls
Examples:  Hit by whirling steel blades
Examples:  Wading through a lava stream
18d10 Examples:  Being submerged in lava
Examples:  Being hit by a crashing flying fortress
24d10 Examples:  Tumbling into a vortex of fire on the Elemental Plane of Fire
Examples:  Being crushed in the jaws of a godlike creature or moon-sized monster

Damage Severity by Level

A dungeon master needs to be careful not to cause excessive improvised damage to a low level party. The table below provides a guideline to how deadly damage can be for characters of various levels.

Dice Examples
1st–4th Examples:  1d10 2d10 4d10
5th–10th Examples:  2d10 4d10 10d10
11th–16th Examples:  4d10 10d10 18d10
17th–20th Examples:  10d10 18d10 24d10

Visit the Thieves Guild for more Resources