Baldur's Gate 3 runs on the Dungeons & Dragons Fifth Edition system, adapted for CRPG by Larian Studios. Although not every tabletop rule and system has made it into the game, Baldur's Gate 3 remains largely faithful and contains many features that will be familiar to Fifth Edition players.
Baldur's Gate 3: Guide to Advantage and Disadvantage
Gaining Advantage (and avoiding Disadvantage) can easily make the difference between victory and defeat in Baldur's Gate 3.