Larian Studios Forums Baldur's Gate III Baldur's Gate III - Help Tips & Tricks Does armor affect spellcasting at all?

5e does not have any penalty for casting with armor.
BUT casters generally are not proficient. (you must be proficient with the type of armor to cast with an armor)

Example : a Mountain Dwarf (5e PHB) can wear medium armor and be a Wizard, with no penalty.

nb : it is not as powerful as it sounds (around 16 AC if you have Dex 14), though sweet. The spell Mage Armor gives as much armor, but it does cost you a spell slot. If you have Dex 16+, Mage Armor will be better.