When a being would be affected by something they are Resistant to, they make a Resistance Save. This is a DC 10 d20 roll that they add their proficiency bonus to if they are proficient in the ability that grants them their Resistance. On a success, the target is not affected by whatever was going to happen to them. On a fail, they are. Resistance Saves cannot be failed automatically. Only one Resistance Save can be attempted per interaction. A Resistance cannot stop a warded ability.