Larian Studios Forums Baldur's Gate III Baldur's Gate III - Help Tips & Tricks How are persuasion modifiers calculated?

The game subtracts your bonuses from the roll target, instead of adding your bonuses to your roll.

Your image says "Roll target 10." This is the total (1d20+5) value you have to get.
The game subtracts your bonuses (+5 from proficiency and Charisma 16) from that target, meaning that you need to roll a 5 on the d20 to pass the check.