Combat actions are Major Actions in which a creature makes an attack roll against a creature's Armor Level (AL) or an ability check against a Contested Score. The Improved Combat Action Martial feat, allow combat actions to be taken as Minor Actions or Quick Actions.
Critical hits & Critical failures
Rolling 1 or 20 PHB p194 [–] Sometimes fate blesses or curses a combatant, causing the novice to hit and the veteran to miss.
If the d20 roll for an attack is a 20, the attack hits regardless of any modifiers or the target's AC. This is called a critical hit, which is explained later in this chapter.
If the d20 roll for an attack is a 1, the attack misses regardless of any modifiers or the target's AC. Unseen Attackers and Targets PHB p194 [–] Combatants often try to escape their foes' notice by hiding, casting the invisibility spell, or lurking in darkness.
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.