Fireball and Lightning Bolt
Both are 3rd-level spells that deal 8d6 damage, fire for Fireball and lightning for Lightning Bolt. Every creature in the area makes a Dexterity saving throw and takes half damage on a success, rounded down.
Roll the 8d6 once and use the same total for everyone caught in it. The roller shows the total, so halving it for the creatures that saved is quick.
Damage at higher levels
Each slot level above 3rd adds one d6. Set the dice count above to match.
| Slot | Dice | Average | Average on a save |
|---|---|---|---|
| 3rd | 8d6 | 28 | 13.75 |
| 4th | 9d6 | 31.5 | 15.5 |
| 5th | 10d6 | 35 | 17.25 |
| 6th | 11d6 | 38.5 | 19 |
| 7th | 12d6 | 42 | 20.75 |
| 8th | 13d6 | 45.5 | 22.5 |
| 9th | 14d6 | 49 | 24.25 |
The averages on a save are a little under half, because each roll is halved and rounded down.
How much will it do?
| Damage | Chance of at least that |
|---|---|
| 20 | 96.1% |
| 24 | 82.1% |
| 28 | 54% |
| 32 | 23.8% |
| 35 | 9.1% |
| 40 | 0.7% |
Eight dice keep the total close to 28: it lands between 22 and 34 about four times in five. If the ogre has 30 hit points left, a failed save drops it 38% of the time. The dice calculator works this out for any roll and any number of hit points.