The spell specifies the ability that the target uses for the save and what happens on a success or failure. The DC to resist one of your spells equals 8 + your spellcasting ability modifier + your proficiency bonus + any special modifiers. Attack Rolls Some spells require the...
AC = The Armor Class you're trying to beat M = Your total to-hit Modifier (including proficiency and ability bonuses) This equation first subtracts your to-hit modifier from your target's AC, which will get you the minimum number you need to roll in order to hit. Once we have th...