Quirinus wrote:he probably means potion stacks. like arrow quivers, that have quantity.
I don't think even that is the best way to do potions. You still have the problem of having to buy as many as you can carry, then spamming them until you run and having to go back to town to refill.
D3's method is better (enemies drop HP globes when they die, bosses drop them when they get below certain %HP breakpoints, and potions have cooldowns), but I think I like PoE's the most (flasks that refill when you kill X enemies or go to town, can be crafted to give certain buffs while active, and have unique versions that are very rare and powerful).
No idea how you could implement PoE's version, but the D3 one miiiiight be doable. You could have enemies have a certain chance of dropping a trap that heals you when triggered, and replace potions with items that cast heal skills with various cool downs. Actually you could probably throw in potions that don't heal you, but grant temporary buffs and have high cooldowns, for a mix of D3 + PoE mechanics.