Yoku

Yoku is the in-run resource of dungeons in Soulbound: Online. It drives the relic system inside a run. It was also once an energy cost you paid to open reward chests, and that part of the mechanic has since been removed from the game.

Yoku And Relics

As you defeat enemies and clear objectives inside a dungeon, Yoku crystals drop and fill your relic experience bar. Each time the bar fills you choose one of three relics to add to your build. In that sense Yoku is the relic experience of a run: more Yoku means more relic picks and deeper synergies before the run ends. Which relics you are offered is shaped by your equipped weapon and abilities and by the upgrades you have already bought.

The Retired Yoku Energy Cost

Yoku used to double as a third energy bar alongside health and stamina. Opening a dungeon's reward chest cost Yoku energy, scaling with difficulty, and the pool refilled daily and could be topped up through contract rewards and consumable items. That cost has been removed: dungeon chests are now claimed for free, and there is no daily Yoku allowance to plan around. Older guides that tell you to ration Yoku between chest openings describe a version of the game that no longer exists.

Several item names still carry the word, including Yoku Forge, Yoku Shard and Yokulite, along with Yoku catfish and the scales crafted from them. Those are ordinary materials and equipment and have nothing to do with the retired energy bar.

Refining Yoku

Rare Yoku can be refined at the chemistry station among your crafting stations, tying the dungeon resource back into base crafting and the wider economy.

Health and stamina are the two energy types the Early Access build actually tracks. Stamina is spent on gathering, at three points per action, and refills passively over time.