A Geas is a spell used to seal an oath or to force someone to do the caster's bidding. Should the target of a geas spell fail in their quest or break their oath, they will suffer dire consequences, like grievous pain and/or death.
The geas spell cannot be dispelled by any conventional means like Dispel Magic or Remove Curse.
There are a few characters under the effect of a geas in the series:
Baldur's Gate I
- Lothander, an assassin in the "employ" of Marek, betrays his master to Gorion's Ward, driven by the prospect of liberation from his geas. A key weakness of poorly worded geases is that they compel obedience without fostering loyalty. To remove his geas, the party must obtain a specially prepared Geas Removal Scroll from High Priestess Jalantha Mistmyr.
Baldur's Gate II
- Yoshimo, a potential companion, is bound by a geas that ultimately compels him to seek death at the hands of the party. If Gorion’s Ward does not recruit him, the geas will kill him regardless. Barring the use of mods, there is no way to save him.
- Viconia DeVir, another recruitable companion, is forced to accept a geas binding her to Gorion’s Ward’s cause when the party exits the Underdark. However, this geas has no mechanical effect in the game: she may still abandon the party if its reputation grows too high or as a consequence of progressing Rasaad’s companion quest. She is arguably released from the geas if, as Gorion’s Ward's romantic partner, she is turned into a vampire during the battle against Bodhi and later restored to life.
Throne of Bhaal
- Sarevok Anchev can be placed under a geas when he joins the party, but this too has limited gameplay consequence. During the final confrontation, Amelyssan dispels it effortlessly with the snap of her fingers.
- Fll’Yissetat, a green dragon, is magically compelled to serve Abazigal by a geas. If the party retrieves the Scroll of Reversal, she can be released from her bondage, allowing for a peaceful resolution to the encounter.