Attack

Whether you're striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has a simple structure.
1. Choose a target. Pick a target within your attack's range: a creature, an object, or a location.
2. Determine modifiers. The GM determines whether the target has Cover and whether you have Advantage or disadvantage against the target. In addition, spells, special abilities, and other effects can apply penalties or bonuses to your attack roll.
3. Resolve the attack. You make the attack roll. On a hit, you roll Damage, unless the particular attack has rules that specify otherwise. Some attacks cause special effects in addition to or instead of damage.
If there's ever any question whether something you're doing counts as an attack, the rule is simple: if you're making an attack roll, you're making an attack.

Attack Rolls

When you make an attack, your attack roll determines whether the attack hits or misses. To make an attack roll, roll a d20 and add the appropriate modifiers. If the total of the roll plus modifiers equals or exceeds the target's Armor Class (AC), then the attack hits. The AC of a character is determined at character creation, whereas the AC of a monster is in its stat block.

Modifiers to the Roll

When a character makes an attack roll, the two most common modifiers to the roll are an ability modifier and the character's proficiency bonus. When a monster makes an attack roll, it uses whatever modifier is provided in its stat block.
Ability Modifier. The ability modifier used for a melee weapon attack is Strength, and the ability modifier used for a ranged weapon attack is Dexterity. Weapons that have the finesse or thrown property break this rule.
Some spells also require an attack roll. The ability modifier used for a spell attack depends on the spellcasting ability of the spellcaster.
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.
Rolling 1 or 20 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.
If the d20 roll for an attack is a 1, it is called a critical miss. The attack misses regardless of any modifiers or the target's AC.

Occupying Hands

If you make a one-handed attack, it occupies one hand. Two-handed attacks occupy two hands. Versatile weapons can be used either one- or two-handed.
Additional Rules for Attacks:

• Ranged Attacks
• Melee Attacks
• Opportunity Attacks
• Two-Weapon Fighting
• Grappling
• Contests
• Attacking Unarmed