Does anyone know if there is a dual-wield penalty (absent a feat), like in 5e? Or does costing a bonus action take the place of the penalty?
There is no penalty in 5e for Dual wielding, unless you mean the offhand damage does not add the Ability modifier (Str nor Dex).
In both 5e, and BG3, the offhand attack cost a Bonus Action.
EDIT : in the current build (Oct. 10, 2020), I noticed you get bonus damage on both attacks, which is an error.
