The most polished isometric CRPG of all time, and given the direction of the gaming industry, probably never to be superseded as such. Like in any CRPG, the gameplay occurs within the dialogue box, and combat is a minigame on the side. What sets
Deadfire apart is that it understands this, and its attention to the details of information delivery smooths away any of the traditional flaws of the format. You never miss important information because you got lazy and skimmed a dialogue box-- in fact, you never skim dialogue boxes, because of their meticulously economical language and the well-delivered voices accompanying them. You never forget a jargon term, because you can mouse over them for a reminder. The story has a subtlety of theme that allows the player to choose between endings in a way that reflects a believable worldview, rather than the classic CRPG foible of presenting the same save-the-world story in a few themed colorways. The game breathes with life without needing to use simulation as a party-trick; its characters live on the strength of the game's writing. All of the skeletal elements of the CRPG art form are done better here than in any other game before or since*.
The rest of the gameplay, while not especially crucial to the experience, holds its weight well enough. The RPG character creation has enough variety to encourage multiple playthroughs, and the combat does its job in creating high moments for each character archetype. Travel and ship combat are weak, but don't detract from the game where it matters.
*If there is one other game which displays an equal understanding of the mechanics of a CRPG text box, it has to be
Disco Elysium. And it's a matter of taste, but
Deadfire includes the player in its world far more thoroughly, while
Disco Elysium treats them as a voyeur to a character study. Like
Deadfire, it will never be replicated.