UNDERDEEP shares the fantasy of a Baldur's Gate 3 style CRPG - attributes, classes, skills, a good and evil axis, and a dungeon to crawl - and none of the structure underneath it. The Underdeep BG3 comparison comes down to one sentence: it is the same fantasy with the campaign and the companions removed, and the session replaced by an optimisation loop that runs in the background.
What UNDERDEEP BG3 shares with a party CRPG
- Attributes that feed a stat block, and classes in the form of jobs that award a fixed pair of stats per stage.
- Skills that are separate from classes and bought with a currency.
- A good and evil axis in the form of Karma, which starts at Neutral (+0) and moves toward Good (+1).
- A dungeon to crawl, with fixed layouts, monsters on a level curve and treasure at the end of it.
If you arrive from Baldur's Gate 3 and read only the character screen, the game looks familiar.
No party, no PvP
You play one character alone. There is no party, no partying and no PvP, and no other player can join your run. The multiplayer is asynchronous and light: a scoreboard, a friend list, gift exchanges and random encounters with other players' characters inside the dungeon. What those encounters are worth is in the other players guide.
No dialogue campaign
The story is a short prologue about a dungeon opening near the royal capital, plus one-time events on the maps that are skill checks with a karma-based alternative. There are no companions, no conversations and no branching narrative, so there is also no persuasion system, no companion opinion to manage and no dialogue to fail.
Combat is not tactical
Combat is one action per turn against one or two monsters. There is no positioning, no cover, no initiative order, no way to choose which enemy you attack, and no defend or flee option in the current build. What you control is decided before the fight, in your stats, your gear and the route you set up - and the health numbers you have to beat are in the monster HP tables.
The pace is an idle loop, not a session
This is the biggest difference in practice. A turn in a narrative RPG takes seconds; a step in UNDERDEEP takes four to five seconds, because a 3-2-1 countdown runs before every action and the text types itself out word by word. The real time sink is the opposite of a session: loop tickets, Vigor and Food budgets, and optimising a farming route that repeats while you are away. The daily numbers are in the loop ticket guide.
Progression is a spreadsheet, not a story
Growth comes from job stages, skills bought with Orbs, gear rarity and drop tables - a set of numbers to push rather than a sequence of scenes to survive. In a party CRPG the session is the unit of progress; here the unit of progress is a repeated route, and the session is what you do while the character runs it.