Battles, Chains & Spell Speed

Once you can summon monsters, you need to know how combat works and how competing card effects resolve. This guide covers the Battle Phase, damage calculation, and the chain system, the rules that decide what happens when multiple effects are used at once. New here? Start with the Beginner's Guide.

The Battle Phase

The Battle Phase runs in four steps, with the middle two repeating for each attack:

Start Step: Announce you are entering the Battle Phase.
Battle Step: Choose one of your face-up Attack Position monsters and one of your opponent's monsters as the target, then declare the attack. If your opponent has no monsters, you attack directly. Each monster gets one attack per turn.
Damage Step: Calculate the result of the battle and any damage.
End Step: End the Battle Phase once you are done attacking.

If the situation changes after an attack is declared but before the Damage Step (a target leaves the field, or a new monster appears), a Replay happens and you re-choose whether and how to attack.

Damage Calculation

Attacking an Attack Position monster: Compare ATK vs. ATK. The higher-ATK monster destroys the other; if equal, both are destroyed. The difference in ATK is dealt to the losing player as battle damage.
Attacking a Defense Position monster: Compare your ATK vs. the defender's DEF. If your ATK is higher, the monster is destroyed but no damage is dealt (unless your monster has piercing). If your ATK is lower, you take the difference as damage. If equal, nothing is destroyed.
Direct attack: With no monsters in the way, the full ATK of your monster is dealt to your opponent's LP.
Piercing battle damage: Some monsters deal the difference between their ATK and the defender's DEF as damage even when attacking a Defense Position monster.

A monster with 0 ATK cannot destroy anything by battle.

Chains

A chain orders the resolution of multiple card effects. Whenever a card or effect is activated, your opponent gets a chance to respond with an effect of their own, building a chain. Each new effect becomes the next Chain Link, stacking on top.

The key rule: a chain resolves in reverse order, so the last effect added resolves first, working back down to Chain Link 1. The response happens before the thing it was responding to.

Example: Player A activates a card that destroys all Spells and Traps (Chain Link 1). Player B responds with a Trap that stops attacks (Chain Link 2). Player A responds with a Counter Trap that negates Player B's Trap (Chain Link 3). Resolution runs from 3 down to 1: Player A's Counter Trap negates Player B's Trap, then Player A's original card resolves successfully.

Note: only activating a card or effect can be responded to. Summoning a monster, Tributing, changing battle position, and paying costs are not activations, so they cannot be chained to.

Spell Speed

Spell Speed decides what can respond to what. You can only respond with an effect that is Spell Speed 2 or higher, and equal to or faster than the effect before it on the chain.

Spell Speed 1: Normal, Equip, Continuous, Field, and Ritual Spells, plus Ignition, Trigger, and Flip monster effects. These cannot respond to anything.
Spell Speed 2: Normal and Continuous Traps, Quick-Play Spells, and monster Quick Effects. Can respond to Spell Speed 1 or 2.
Spell Speed 3: Counter Traps only. Can respond to anything, and only another Spell Speed 3 card can respond to them.

Priority

The turn player always gets the first chance to act (Priority) in each phase or step. They can use it to activate a card, or pass to let the opponent act. Priority passes to the opponent after each activation and at the end of every phase or step.

That covers the core engine of the game. To review the pieces, see Card Types and Summoning, or check unfamiliar terms in the Glossary.