An attack roll is a roll to determine whether an attack made by a character or creature is successful in hitting its intended target. When a character or creature declares it is making an attack, the following steps typically occur:
1. Roll a d20:
The attacker rolls a twenty-sided die.
- Advantage. If the attacker has one advantage or three advantages on the attack roll, the attacker rolls two or three d20s respectively, and takes the higher of the two or three.
- Disadvantage. If the attacker has one disadvantage or three disadvantages on the attack roll, the attacker rolls two or three d20s respectively, and takes the lower of the two or three.
2. Modifiers:
To the result of the d20 roll, the attacker adds relevant modifiers. These modifiers include:
- Proficiency Bonus. The character or creature adds their proficiency bonus if applicable. Spellcasting always adds their proficiency bonus.
- Ability Modifiers. Their relevant ability modifier (e.g., Strength for melee attacks, Dexterity for ranged attacks, or a spellcasting modifier for spell attacks).
- Bonus Modifiers. Any additional bonuses from magical weapons, class features, or other situational effects.
The defender adds relevant temporary bonuses or situational effects to their AL, for example cover bonuses.
- Cover Bonus. ..............................
3. Compare the Total to the target's Armor Level (AL)
The total result is compared to the Armor Level of the target. If the attacker's total is equal to or greater than the target's AC, the attack hits. If it's lower, the attack misses.
- Critical hits & Critical misses. ==Critical Success==
A critical success is achieved when a check meets or exceeds the result of a check's DL or the AL of a target by 10 or more. When this check is made to deal damage, like an attack or spell effect, it is usually referred to as a critical hit.
Critical Hit Damage
When you critically hit, i.e. have a critical success on a check that deals damage, the damage is doubled after all positive modifiers have been applied.
Natural 20
If you roll a 20 on the check, the result is one degree higher than it should be. This usually results in a critical success, but can result in a success or a failure if the DL is very high.
Critical Failure
A critical failure is achieved when a check fail to meet the result of a check's DL or the AC of a target by 10 or more.
Natural 1
If you roll a 1 on the check, the result is one degree lower than it should be. This usually results in a critical failure, but can result in a only a failure or a success if the DL is very low.
4. Roll for Damage
If the attack hits, the attacker typically rolls dice to determine the amount of damage dealt. The type and number of dice rolled depend on the weapon, spell, or attack being used.
An example might be a warrior trying to hit an enemy goblin with a sword. The player would roll a d20, add their proficiency bonus and Strength modifier (if it's a melee attack), and compare the total to the goblin's AC. If the result is equal to or greater than the goblin's AC, the attack is successful, and the player would then roll damage dice to determine how much damage is dealt to the goblin.
Critical hits & Critical misses
When you attack a target that you can't see, you have disadvantage on the attack roll. This is true whether you're guessing the target's location or you're targeting a creature you can hear but not see. If the target isn't in the location you targeted, you automatically miss, but the DM typically just says that the attack missed, not whether you guessed the target's location correctly.
When a creature can't see you, you have advantage on attack rolls against it.
If you are hidden—both unseen and unheard—when you make an attack, you give away your location when the attack hits or misses.
Ranged Attacks PHB p195 [–] When you make a ranged attack, you fire a bow or a crossbow, hurl a handaxe, or otherwise send projectiles to strike a foe at a distance. A monster might shoot spines from its tail. Many spells also involve making a ranged attack.
Range PHB p195 [–] You can make ranged attacks only against targets within a specified range.
If a ranged attack, such as one made with a spell, has a single range, you can't attack a target beyond this range.
Some ranged attacks, such as those made with a longbow or a shortbow, have two ranges. The smaller number is the normal range, and the larger number is the long range. Your attack roll has disadvantage when your target is beyond normal range, and you can't attack a target beyond the long range.
Ranged Attacks in Close Combat PHB p195 [–] Aiming a ranged attack is more difficult when a foe is next to you. When you make a ranged attack with a weapon, a spell, or some other means, you have disadvantage on the attack roll if you are within 5 feet of a hostile creature who can see you and who isn't incapacitated.
Melee Attacks PHB p195 [–] Used in hand-to-hand combat, a melee attack allows you to attack a foe within your reach. A melee attack typically uses a handheld weapon such as a sword, a warhammer, or an axe. A typical monster makes a melee attack when it strikes with its claws, horns, teeth, tentacles, or other body part. A few spells also involve making a melee attack.
Most creatures have a 5-foot reach and can thus attack targets within 5 feet of them when making a melee attack. Certain creatures (typically those larger than Medium) have melee attacks with a greater reach than 5 feet, as noted in their descriptions.
Instead of using a weapon to make a melee weapon attack, you can use an unarmed strike: a punch, kick, head-butt, or similar forceful blow (none of which count as weapons). On a hit, an unarmed strike deals bludgeoning damage equal to 1 + your Strength modifier. You are proficient with your unarmed strikes.
Contests in Combat PHB p195 [–] Battle often involves pitting your prowess against that of your foe. Such a challenge is represented by a contest. This section includes the most common contests that require an action in combat: grappling and shoving a creature. The DM can use these contests as models for improvising others.
Common Modifiers
- Ability Modifier.
- Strength is used for melee cleaving, splitting and bludgeoning attack and damage rolls.
Dexterity is used for melee slashing and piercing attack and damage rolls, as well as ranged attack rolls (including throwing). - Draw strength determines the added ranged damage for drawn and loaded weapons, while the melee ability modifier (Strength or Dexterity) determines the thrown weapons added damage (i.e. a thrown bludgeoning weapon uses strength, while a piercing dagger will use Dexterity).
- The ability modifier used for a spells depends on the Spellcasting ability of the spellcaster.
- Strength is used for melee cleaving, splitting and bludgeoning attack and damage rolls.
- Proficiency Bonus. You add your proficiency bonus to your attack roll when you attack using a weapon with which you have proficiency, as well as when you attack with a spell.
- Cover. Walls, trees, creatures, and other obstacles can provide cover during combat, making a target more difficult to harm. A target can benefit from cover only when an attack or other effect originates on the opposite side of the cover.