Expert (talent)

Essential. Become an expert in one skill or tool in which you are already proficient. Being an expert lets you add a bonus die to applicable ability checks. The size of the die depends on your proficiency bonus: d4 for a +2 bonus, d6 for +3, d8 for +4, d10 for +5, and d12 for +6. Being an expert in a subject also counts as having "expertise" in a subject. The effects can't combine.