What the Thief is meant to do
The Underkeep thief class is a weapon-focused character with an evasion-based front-line role, according to developer discussion. Daggers are central to its skill compatibility, while some skills also work with swords. That gives the class a clearer identity than simply assuming it is the mandatory chest-opening member of every party.
In the developer's February class discussion, Thief is named as a character capable of filling a front-line role through evasion. The same reply distinguishes swords from daggers and explains that most Thief skills work with daggers, with some also accepting swords.
Check the weapon requirement before equipping
If you are planning a Thief, read each available skill's requirement before changing weapons. A sword and a dagger are not interchangeable merely because both fit the character's fantasy. The developer explicitly treats them as separate weapon types.
That means a practical equipment check is to compare the weapon's requirements with the skill you intend to use, rather than choosing purely by its displayed damage. The supplied material does not include a complete final skill tree, so it cannot establish one weapon as best for every Thief ability.
Dual wielding also needs a version check. In a March developer response, it was described as a planned specialization shared by Thief and Warrior. That is not a confirmed instruction to equip two daggers in the public demo.
Separate the class plan from demo availability
The February developer comments discuss the Thief's role, but the March response still lists Thief among classes planned for the full game and acknowledges the demo's limited roster. These statements should not be combined into an invented unlock quest or a claim that every public demo offers the class.
If Thief does not appear in your creation screen, check your version and the official Underkeep page. The supported answer here is its confirmed role and weapon relationship, not a hidden procedure for making an unavailable class appear.
Similarly, a player's concern that a Thief might become necessary for locks or traps is speculation. The cited replies do not establish an exclusive lockpicking rule or prove that a party without a Thief cannot finish the game.
FAQ
Can a Thief stand in the front line?
The developer describes an evasion-specialized Thief as capable of a tank-like front-line role. That does not provide a tested universal build or guaranteed avoidance.
Do all Thief skills work with swords?
No. The developer says most work with daggers and some also work with swords. Check the individual skill rather than assuming full compatibility.
How do I unlock Thief in the demo?
The available material does not establish a demo unlock method. Developer comments distinguish the limited demo roster from classes being developed for the full game.