AT A GLANCE

The Cube is not one button. This page tells you what each operation consumes, when it unlocks, and which items should never go into auto-fill.

Keep equipment that supports the active formation; use Alchemy for true surplus, Synthesis only when all nine inputs are expendable, and treat permanent-effect operations as irreversible decisions.

TBH Hero-dric Cube: a decision guide, not a button list

The Cube is TBH’s item economy. It gives you a way to turn drops into Gold, move up gear grades, target a slot, and add or remove permanent item effects. The useful question is not “what does this tab do?” but “what am I giving up by pressing confirm?”

All eight operations and when they unlock

Operation	Unlock	Cost shown by current database	Use it for
Synthesis	Default	—	9 same-grade items in one category → one higher-grade result
Alchemy	Cube Lv 1	10 Gold	Surplus items → Gold + Cube EXP
Crafting	Cube Lv 5	100 Gold	A random item in a selected slot/category
Decoration	Cube Lv 8	300 Gold	Add a special stat/material effect
Extraction	Cube Lv 10	1,000 Gold	Remove an applied effect; material is not returned
Engraving	Cube Lv 15	1,000 Gold	Add an engraving effect
Offering	Cube Lv 20	3,000 Gold	Trade commemorative coins for a random reward
Inscription	Cube Lv 25	10,000 Gold	Add an inscription effect

The unlock levels and operation names come from a community-datamined database. The official Steam page confirms the Cube system, but does not publish the full recipe table.

The keep / alchemize / synthesize rule

Before opening the Cube, sort every item into one of four piles:

Pile	Keep it when…	Cube action
Equipped	a hero is wearing it	never auto-fill
Backup	it is the only spare for an active role or a better base grade	keep until the replacement is tested
Market candidate	it is tradable and high grade, with no applied effects	check the market before consuming
Surplus	it is a duplicate you cannot equip, sell, or use in a planned recipe	Alchemy or Synthesis

Lock valuable items before using auto-fill. The community guide documents Alt + Left Click; confirm the lock icon in your client before trusting the shortcut.

Synthesis: exact rules that matter

Synthesis takes nine items of the same grade and the same category. Gear, Accessories, and Materials cannot be mixed. The result is rolled around the input level range and can be a higher grade; at high grades, a same-grade result is possible.

Inputs	Current datamined result rule
9 Common	95% Uncommon; 4.8% Rare great success
9 Uncommon	96% Rare; 3.8% Legendary great success
9 Rare	98% Legendary; 2.4% Immortal great success
9 Legendary	99% Immortal; 0.99% Arcana great success
9 Immortal	50% Immortal; 50% Arcana; 0.25% Beyond great success

Below Immortal, the normal result grades up. From Immortal upward, a synthesis can fail into the same grade. That is why “nine items = guaranteed upgrade” is bad advice for late-game gear.

Alchemy: the safe early Gold button

Alchemy consumes 1–9 items and returns Gold plus Cube EXP. Current database base Gold values are:

Grade	Base Gold
Common	10
Uncommon	30
Rare	90
Legendary	270
Immortal	810
Arcana	2,592

Rune and pet bonuses can increase the actual payout. Equipped, blocked, and reserved items should not be treated as disposable. If the auto-fill list contains one item you cannot replace, cancel and lock it.

Crafting: target a slot, accept randomness

Crafting lets you choose a gear slot—main weapon, off-hand, helmet, armor, gloves, boots, or accessory—and returns a random item from the selected tier. It does not promise a specific name, grade, or perfect stat line. Use it when you can name the missing slot; do not use it as a blind “upgrade” button.

Permanent effects: wait for the base item

Decoration, Engraving, and Inscription spend materials on an item. Extraction removes an applied effect, but the material used to add the effect is not returned in current data. Therefore:

1. Equip the base item.
2. Test it for several stages.
3. Confirm the class and role you want to keep.
4. Apply the effect.
5. Extract only when the replacement is demonstrably better.

Offering is a random reward exchange. It may be useful for excess commemorative coins, but it is not a reliable fix for a progression wall.

Cube-level priorities

Every item consumed by Synthesis, Alchemy, Crafting, and Offering grants Cube EXP; Decoration, Engraving, Inscription, and Extraction do not. Higher-grade, higher-level materials give more EXP, but level mismatch reduces the gain. This makes Alchemy a legitimate early leveling route when the items are already surplus—not a reason to destroy your active set.

Sources and evidence

• TBH Wiki Cube overview — operation unlock levels, costs, Cube EXP and database formulas.
• TBH Wiki Synthesis — 9-item category rules, grade odds and high-grade failure behavior.
• TBH Wiki Alchemy — base Gold values and item restrictions.
• Official Steam listing — official high-level Cube description.

The datamined pages are independent fan references. Use them for exact tables, then check the live Cube tooltip after a patch.