When your items run out of Ammo, gain 10 » 20 » 30 Regen for the fight.

The first time you fall below half Health each fight, gain 1 » 2 times your Regen for the fight.

When you use a Food, Slow it for 1 second and gain 3 » 6 Regen for the fight.

When you use a Friend, gain 2 » 4 Regen for the fight.

You have +3 » +6 » +9 Regen for each non-Weapon item you have.

When you Burn, gain 2 » 4 Regen for the fight.

You have +Regen equal to half the Burn on an enemy.

The first 5 » 10 times you use a Toy each fight, gain 5 Regen for the fight.

When you Poison, gain 2 » 4 Regen for the fight.

The first 5 » 10 times you use a Chilled item each fight, gain 10 Regen for the fight.