A Heart Canister is an item that permanently increases your maximum health by one heart (2 health) per canister equipped, up to a maximum of 20 hearts (40 health). They are used by either right clicking with them, or by placing them in the appropriate slot in the 'e' menu. The extra hearts are shown as orange and cover up the standard red health, rather than be shown above them. They are useful for exploring and battling monsters.
Should you die, you will not lose the canisters due to how the Accessory slots work. However, you will respawn with 10 hearts of health regardless, but your extra health will still regenerate from natural health regeneration. You can put a total of 30 canisters in your Accessories on the right, but only the 10 in the Canister slot will work.
- A player can remove their heart canisters so that they have more health than their maximum until they take damage. For example, if you have one heart canister and 11/11 hearts, and you take it out of your "O" menu slot, you will have 11/10 hearts. Your health will therefore not regenerate until you reach 9.5 or fewer hearts.
- Healing in any way when under effect of this "bug" will set the health to the current maximum. Whatever health you have over 10 hearts when you remove the canisters will stay as actual health until it is lost. Utilizing this, you may effectively pass around a set of 10 canisters to a party and have everyone have up to 20 (temporary) hearts with only a single set. However, Regeneration or Regeneration-based effect will not set the health back to the current maximum (due to how regeneration work), this 'bug' also happen to Infernal Mobs, where the mobs have health over-limit and it's max health is default.
- The Heart Canister is currently the only item that has its own reserved slot (Like the Knapsack) in the Accessories on the Armor tab. The Knapsack is located in the Gear area of the Armor Tab, however, and not the accessories.
- When regenerating health using a source of Regeneration I or II, the orange hearts do not jump up and down like the red ones do. This is not a bug, as it was never coded that way.