In UNDERDEEP, Orbs won in fights buy your skills, and skills unlock by how many items you have gathered at each rarity tier - not by levelling. The Underdeep skills and orbs guide below is the shopping list: what to buy with your Orbs, what to refuse, and when an extra skill slot is worth the currency.

Skills unlock by how many items you hold

  • Normal items unlock the Normal skill range, N1 to N81.
  • Rare items unlock the Rare skill range, R1 to R174.
  • Super Rare items unlock the Super Rare range, SR1 and upward.

All Normal and Rare skills are straightforward to unlock. The Super Rare and SSR ranges stay locked behind rare drops, which is why your skill slots can run out long before the best skills are available. The rarity tiers themselves are explained in the item rarity guide.

What to buy with Orbs first

  1. Buy as many skills as possible for your main attacking stat first. If you can kill a boss before it kills you, the remaining skills barely matter.
  2. Only buy another skill slot once your current slots are completely full.
  3. Round out Dexterity, Sense and Toughness with skills rather than jobs, because Orbs are far more common than job experience points.
  4. Take potion-capacity skills when your damage or health cannot kill a boss before it kills you.

Which stat those skills should push depends on the weapon you run, and the build guide has the priority order that decides it.

Underdeep skills and orbs guide: what to buy and what to skip

  • Attack-style skills if you only ever use one weapon style.
  • Potion-drinking skills. Potions rarely out-heal a boss unless you have invested heavily in HP, and you can drink after a fight for free using an E marker.
  • Personality skills. Each fight wastes time typing out the personality line, and the skill occupies a slot while granting nothing mechanical.
  • Element-boosting skills, unless you are running an AOE weapon of the matching element.

Skill slots and where Orbs come from

Orbs drop from fights and are spent in the Skill tab, which buys individual skills and extra slots. The Shop panel is a separate currency path for skill advances, and it is worth understanding the difference before you spend either one.