White Potion

The White Potion is the workhorse HP recovery item of the 20-40 level range. Restores a big chunk of HP per pop, cheap enough to buy in stacks of 100 without flinching, and sold by almost every town's general potion vendor. If you're a Warrior training past level 25, you'll go through hundreds of these per grinding session - it's basically part of the training cost budget.

Magicians typically skip White Potions in favor of Mana potions (thanks to Magic Guard converting damage-to-MP - see the Magician guide). Everyone else is buying these by the stack.