The Attack Action, Actually Explained
Rolling to hit is the most repeated action in D&D, and it’s also one of the most misunderstood. There are three steps: pick your target, apply your modifiers, resolve the attack. The rules make that sound simple. The modifiers are where the real shape of combat lives.
Making the Attack Roll
Every attack roll is a d20 plus your ability modifier plus your proficiency bonus, if you have it. For melee, that ability score is usually Strength, unless your weapon has the finesse keyword, in which case you can use Dexterity instead. Rapiers, daggers, and short swords fall into this category. Anything you’re swinging hard, like a greataxe or a warhammer, uses Strength. Ranged attacks use Dexterity. That number gets compared to the target’s Armor Class, and you need to meet or beat it.
AC is worth a second look here. It’s not just armor absorbing hits. The Dexterity modifier a lightly armored character adds to their AC represents dodging, reading movement, not being where the sword lands. A monk with leather and high DEX is hard to hit because they’re hard to catch, not because they’re well padded.
Criticals work exactly as the rules say and no more. A natural 1 fails, a natural 20 hits, full stop. The nat 20 bypasses AC entirely, meaning a level 1 character with a fist can technically land a blow on a creature with 30 AC. The extra damage from a critical is covered separately in the damage rules, but the hit itself is unconditional.
Ranged and Melee
Ranged weapons list two numbers for range, something like 120/600. Inside the first number you roll normally. Between the two numbers you roll with disadvantage. Beyond the second number, the attack is impossible. What catches people off guard is the close end of that range: if a hostile creature is within 5 feet of you, you also roll with disadvantage on your ranged attack, even if you’re targeting something further away. It’s not about distance to the target. It’s about having someone in your face while you try to aim.
Melee attacks reach 5 feet by default. Weapons with the reach property extend that to 10 feet. Size interacts with this too: a Large creature controls a larger square, so adjacent targets are already further out, which effectively extends their threat range.
Grappling and Shoving
Both of these replace the normal attack roll with an ability check contest. You roll Athletics. They roll Athletics or Acrobatics, their choice. Win the grapple and you control their movement, dragging them at half speed. Win the shove and you either push them 5 feet back or knock them prone.
Prone matters because attacks against prone creatures from adjacent squares have advantage, and getting advantage on attack rolls is one of the more reliable ways to tilt combat. The shove is also an underrated setup move for any grappler build.
For two-weapon fighting, the second attack is a bonus action, not part of the Attack action itself. The catch is that you do not add your ability modifier to the damage roll of the bonus attack, unless that modifier is negative, in which case it applies as a penalty. Both weapons must have the light property to qualify.
For additional reference, see Player’s Handbook Chapter 9: Combat (Attack Rolls, Making an Attack, Two-Weapon Fighting, Grappling).