Health Regeneration

Health regeneration (or "health regen") is the rate at which a champion passively restores health, usually measured per five seconds. It lets you recover between fights and stay in lane longer without recalling to base.

Unlike lifesteal and omnivamp, which heal you while you deal damage, regen ticks steadily on its own and is strongest when you are out of combat. It comes from base stats, certain items and runes, and is most noticeable on tanky champions. Sustainable lane presence built on good regen is a quiet but real advantage in the early game.