Stand beside an anvil and choose Temper gear. Pick a weapon, shield, helmet, body armour, legs or boots from your bag or worn gear, review the bonus, then confirm. One stone is consumed, no gold. Tools, ammunition, capes and jewellery are excluded.
Tempering adds 5% of the main stat, rounded to the nearest whole number, at least +1: melee attack, ranged attack, bolt power, armour or shield defence. Offensive staffs also gain 5% of their existing spell-power bonus, added as percentage points. It does not change level requirements or special effects. Each piece can be tempered once, including legendary and soulbound gear. Soulbinding and tempering add their bonuses independently, in either order.
Tempered gear keeps its bonus through the bank, trading, the Town Market, saves and death. Soulbound gear still cannot change hands. Oathbound adventurers may temper their own gear with stones earned from their boss shares; trade, market and foreign-loot restrictions remain unchanged.
Every boss makes one independent stone roll per defeat, not one per fighter. One eligible fighter receives it, weighted by contribution; eligible fallen fighters keep their share. Base chances are 1 in 1,000 up to level 100, 1 in 600 at levels 101–135, and 1 in 400 above that. The existing creature drop factor applies, so these are not guaranteed farming times. Stones are never sold by shops, crafted or bought for real money.