ATK/DEF Modifier Application Order

When several effects change a monster's ATK or DEF at once, you do not just add everything up. Modifiers fall into distinct classes, and the class decides whether a modifier stacks, freezes a value, re-reads current game state, or wipes earlier modifiers. Getting the order of application wrong is a common Judge failure that produces a plausible-but-wrong final ATK.

This page is the general modifier-ordering framework. For the narrower "two effects both set the same value, last one applied wins" case see Continuous Application Effects; for "is the value rebuilt after negation / on revival" see ATK Effects: Past Summon Facts vs Current Game State.

The classes of modifier

1. Additive increases/decreases ("gains/loses X ATK"). These stack onto the current value and are continuously recalculated against current game state. ATK/DEF cannot show below 0, but accumulated decreases keep subtracting "in the background" and offset later increases.
2. Activated effects that SET or multiply the current value ("becomes X", "is doubled/halved"). These freeze the value at the number determined when the effect resolves. They overwrite earlier modifiers and do not recompute later — the snapshot is locked in.
3. Non-activated (continuous) effects that SET the current value. These mask earlier modifiers while they apply, but re-apply prior additive modifiers on top of the set value. If the continuous effect later stops, the masked modifiers reappear.
4. Effects that change the ORIGINAL ATK/DEF. When original ATK changes, additive modifiers re-apply on the new base, but earlier activated set/multiply effects (class 2) are wiped forever and never come back.
5. Special continuous effects flagged "applied last" (certain halving floodgates): re-applied after everything else resolves, so they sit on top of the final number.

The governing idea: additive modifiers are time-stamped and recalculated; an activated "set/×" effect takes a snapshot and freezes it. That is why activation order changes the answer.

Verbatim text

Barrel Dragon — printed 2600 ATK / 2200 DEF, Machine.

Mage Power — "The equipped monster gains 500 ATK and DEF for each Spell/Trap Card you control."

Limiter Removal — "Double the ATK of all Machine monsters you currently control, until the end of this turn. During the End Phase of this turn, destroy those monsters."

Worked example — additive recalculates, then the ×2 snapshots

"Barrel Dragon is equipped with Mage Power (it is my only Spell/Trap), so it is 3100/2700. I activate Limiter Removal from my hand. What is its ATK?"

— Answer: 7200 ATK. Start: 2600 base + 500 (Mage Power reads 1 Spell/Trap = itself) = 3100. The moment Limiter Removal is placed in the Spell/Trap Zone, Mage Power is an additive modifier (class 1) and recalculates against the new count — now 2 Spell/Traps — so it gives +1000 → 3600. Then Limiter Removal resolves and doubles that current 3600 (class 2 snapshot) → 7200.

The order matters: the additive Mage Power sees the extra Spell/Trap before the doubling snapshots, so you double 3600, not 3100. If you instead doubled first and added later you would get the wrong number.

What happens to a frozen "set/×" value later

• A later additive modifier is applied on top of the frozen value — but if that frozen value is itself later overwritten, "changes made by previous activated effects to the current ATK/DEF are never reapplied; they have been wiped forever."
• The original ATK is later changed → "previously-applied activated effects that set the monster's current ATK/DEF to a determined value are wiped, and not reapplied." Additive (class 1) and continuous-set (class 3) modifiers re-apply on the new base; the frozen class-2 snapshot does not.
• A continuous (class 3) set-effect's source leaves → the modifiers it had been masking are re-applied: "if the new effect stops applying after a certain duration, a continuously-applied effect's modifiers are reapplied."

Original DEF is not current DEF — D2 Shield, Shield & Sword, Maju Garzett

Effects that double or set current ATK/DEF do not rewrite the monster's original ATK/DEF. When a later effect swaps or reads original values, ignore a temporary boost or other temporary current-stat boosts unless the card explicitly changed the original value.

D2 Shield doubles a Defense Position monster's current DEF. If it doubles Destiny HERO - Defender from 2700 DEF to 5400 DEF, the monster's original DEF is still 2700.

Shield & Sword switches the original ATK and original DEF of all face-up monsters. It uses the printed/original values, not the current DEF doubled by D2 Shield. So Destiny HERO - Defender's ATK becomes its original DEF value, not 5400.

Maju Garzett reads the original ATK of the Tributed monsters. Temporary current-stat boosts do not become the Tributed monsters' original ATK, so they do not inflate Maju Garzett's ATK.

The transfer rule: current DEF / current ATK is not original DEF / original ATK. Before answering a stat question, identify whether the card says current, original, becomes, gains, doubles, halves, or swaps.

Generalized principle

Before stating a final ATK, classify every modifier present:

• additive (recalculates, stacks),
• activated set/× (freezes a snapshot, can be wiped by a later original-ATK change),
• continuous set (masks but re-applies additives, reversible when it stops),
• original-ATK change (rebases; wipes activated set snapshots),
• "applied-last" floodgate.

Then apply them in that interaction order against current game state. Never sum blindly, and never assume a doubling/halving re-reads later — it took its snapshot at resolution.

Judge calls to watch for

• An additive "gains X for each …" modifier (Mage Power, field-count buffs) recalculates continuously; an activated "becomes X" / "is doubled" effect snapshots once and freezes. Resolve the additive change before the snapshot if it happens first.
• Temporary current-stat boosts such as D2 Shield do not change original ATK/DEF. Effects like Shield & Sword and Maju Garzett that read original values ignore those temporary current-stat boosts.
• Activation order of a buff and a doubler changes the result — ask which resolved when before giving a number.
• Changing a monster's original ATK wipes earlier activated set/× effects permanently; they do not return when the original-ATK effect ends.
• A continuous set-value effect only masks earlier additive modifiers; those reappear if it stops (reversible), unlike an activated set effect (wiped).
• ATK/DEF never displays below 0, but accumulated decreases keep subtracting behind the scenes and cancel later increases.
• Don't conflate this with Continuous Application Effects's "two set-values, last applied wins" — that is the special case of class 2/3 conflicts; this page is the full ordering across all classes.