In some cases you need to determine damage on the fly. The Improvising Damage table gives you suggestions for when you do so.
| Improvising Damage | |
| Dice | Examples |
| 1d10 | Burned by coals, hit by a falling bookcase, pricked by a poison needle |
| 2d10 | Being struck by lightning, stumbling into a fire pit |
| 4d10 | Hit by falling rubble in a collapsing tunnel, stumbling into a vat of acid |
| 10d10 | Crushed by compacting walls, hit by whirling steel blades, wading through a lava stream |
| 18d10 | Being submerged in lava, being hit by a crashing flying fortress |
| 24d10 | Tumbling into a vortex of fire on the Elemental Plane of Fire, being crushed in the jaws of a godlike creature or a moon-sized monster |
The Damage Severity and Level table is a guide to how deadly these damage numbers are for characters of various levels. Cross-reference a character's level with the damage being dealt to gauge the severity of the damage.
| Damage Severity and Level | |||
| Character Level | Setback | Dangerous | Deadly |
| 1st-4th | 1d10 | 2d10 | 4d10 |
| 5th-10th | 2d10 | 4d10 | 10d10 |
| 11th-16th | 4d10 | 10d10 | 18d10 |
| 17th-20th | 10d10 | 18d10 | 24d10 |
Damage sufficient to cause a setback rarely poses a risk of death to characters of the level shown, but a severely weakened character might be laid low by this damage.
In contrast, dangerous damage values pose a significant threat to weaker characters and could potentially kill a character of the level shown if that character is missing many hit points.
As the name suggests, deadly damage is enough to drop a character of the level shown to 0 hit points. This level of damage can kill even powerful characters outright if they are already wounded.