Dungeon Master: Roll Half Health

A bit of randomness helps spice things up and make things different. The Dungeon Master has many tools to incorporate randomness such as rolling health. However, keeping things balanced and fair is important as well. For this reason, I hope to share a little trick I use when rolling health for combat encounters.

Roll Half Health

To add a bit of randomness but to ensure that the combat encounter doesn't become much more difficult, roll for only half of the enemies of the same type (rounding down in the case of odd numbers). Then match up the rolled enemies with unrolled enemies and make the health of the unrolled enemy to be 2 * average health – rolled health. This way, the overall amount of health in the encounter remains the same. However, some creatures will have more health and some will have less. In the worst case scenario, half will have really low health and half will have really high. The number of enemies rolled for can be reduced if less randomness is desired (if there are 6 kobolds, roll for one and match it with one).

Example

4 kobolds are going to be used (using 5^th edition Dungeons & Dragons rules). Rolled 3 and 4. Final health is 3, 4, 7 (2 * 5 – 3 = 7), 6 (2 * 5 – 4 = 6). Average health for a kobold is 5.

Used as Guideline

Even without rolling, the basic idea can be used. If you know you'd like to keep the same amount of health but have one of the NPCs to be weaker than the others, you can decide that one of the kobolds will have 4 health (meaning that another will have 6).