Negation And Immunity

Many card effects say "negate", "unaffected", "cannot be targeted", or "cannot be destroyed". Those phrases are related, but they are not the same script shape.

Use this page when the effect changes whether another effect applies to a card or Chain Link. If the effect moves the card instead, start with Functions that move cards across locations.

Choose The Correct Mechanic

Card text shape	Usual script tool
"Negate the activation..."	`Duel.NegateActivation` during the negating effect's operation.
"Negate that effect..."	`Duel.NegateEffect` during the negating effect's operation.
"That monster's effects are negated until..."	Register `EFFECT_DISABLE` and `EFFECT_DISABLE_EFFECT` on that monster.
"Unaffected by..."	Register `EFFECT_IMMUNE_EFFECT` and provide a value filter.
"Cannot be targeted by..."	Register `EFFECT_CANNOT_BE_EFFECT_TARGET`.
"Cannot be destroyed by card effects..."	Register `EFFECT_INDESTRUCTABLE_EFFECT` or a destroy replacement effect.

Negation usually answers "does this Chain Link or card effect apply?" Immunity and protection answer "can this outside effect touch this card at all?"

Negating An Activation

Cyber Dragon Infinity (c10443957.lua) is a clean local example. Its Quick Effect responds to EVENT_CHAINING, checks whether the Chain Link can be negated, detaches material as cost, then negates the activation and destroys the activating card only if the negation succeeded:

lua

function s.discon(e,tp,eg,ep,ev,re,r,rp)
    return not e:GetHandler():IsStatus(STATUS_BATTLE_DESTROYED)
        and Duel.IsChainNegatable(ev)
end

function s.disop(e,tp,eg,ep,ev,re,r,rp)
    if Duel.NegateActivation(ev) and re:GetHandler():IsRelateToEffect(re) then
        Duel.Destroy(eg,REASON_EFFECT)
    end
end

The target function should announce both categories:

lua

Duel.SetOperationInfo(0,CATEGORY_NEGATE,eg,1,0,0)
if re:GetHandler():IsDestructable() and re:GetHandler():IsRelateToEffect(re) then
    Duel.SetOperationInfo(0,CATEGORY_DESTROY,eg,1,0,0)
end

The important part is the return value. Duel.NegateActivation(ev) returns a boolean. Follow-up actions such as destroy, banish, send to the GY, or Set are usually gated behind that return.

Negating Only The Effect

Use Duel.NegateEffect when the card text negates the resolving effect but not the activation itself. Infinite Impermanence (c10045474.lua) uses it for the same-column Spell/Trap lock while a Chain Link is solving:

lua

function s.disop(e,tp,eg,ep,ev,re,r,rp)
    local tseq=e:GetLabel()
    local controller,loc,seq=Duel.GetChainInfo(ev,
        CHAININFO_TRIGGERING_CONTROLER,
        CHAININFO_TRIGGERING_LOCATION,
        CHAININFO_TRIGGERING_SEQUENCE)
    if loc&LOCATION_SZONE~=0 and seq<=4 and re:IsActiveType(TYPE_SPELL+TYPE_TRAP)
        and ((controller==tp and seq==tseq) or (controller==1-tp and seq==4-tseq)) then
        Duel.NegateEffect(ev)
    end
end

That pattern is different from "negate the activation". The Chain Link still exists, but its effect is negated.

Negating A Card's Effects Until A Time

Effect Veiler (c97268402.lua) shows the common temporary monster-negation shape:

lua

function s.operation(e,tp,eg,ep,ev,re,r,rp)
    local c=e:GetHandler()
    local tc=Duel.GetFirstTarget()
    if tc:IsFaceup() and tc:IsRelateToEffect(e)
        and tc:IsControler(1-tp)
        and tc:IsCanBeDisabledByEffect(e) then
        Duel.NegateRelatedChain(tc,RESET_TURN_SET)
        local e1=Effect.CreateEffect(c)
        e1:SetType(EFFECT_TYPE_SINGLE)
        e1:SetCode(EFFECT_DISABLE)
        e1:SetReset(RESET_EVENT+RESETS_STANDARD+RESET_PHASE+PHASE_END)
        tc:RegisterEffect(e1)
        local e2=Effect.CreateEffect(c)
        e2:SetType(EFFECT_TYPE_SINGLE)
        e2:SetCode(EFFECT_DISABLE_EFFECT)
        e2:SetValue(RESET_TURN_SET)
        e2:SetReset(RESET_EVENT+RESETS_STANDARD+RESET_PHASE+PHASE_END)
        tc:RegisterEffect(e2)
    end
end

There are three lessons packed into that small operation:

Piece	Why it is there
`Card.IsCanBeDisabledByEffect`	Checks whether this effect is allowed to disable the target now.
`Duel.NegateRelatedChain`	Handles already-created Chain Links related to the target.
`EFFECT_DISABLE` plus `EFFECT_DISABLE_EFFECT`	Applies the visible "effects are negated" state to the monster until reset.

For temporary negation, always think about reset. A missing reset creates a lingering rule that lasts much longer than the card text says.

Immunity

Immunity is not the same as negation. An unaffected card is still allowed to have active effects, but outside effects that match the immunity filter do not apply to it.

The Winged Dragon of Ra - Immortal Phoenix (c10000090.lua) registers EFFECT_IMMUNE_EFFECT while it is in the Monster Zone:

lua

local e3=Effect.CreateEffect(c)
e3:SetType(EFFECT_TYPE_SINGLE)
e3:SetCode(EFFECT_IMMUNE_EFFECT)
e3:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
e3:SetRange(LOCATION_MZONE)
e3:SetValue(s.efilter)
c:RegisterEffect(e3)

function s.efilter(e,te)
    return te:GetOwner()~=e:GetOwner()
end

For EFFECT_IMMUNE_EFFECT, the value is usually a function. It receives the immunity effect and the incoming effect being tested. Return true when the incoming effect should not affect the protected card.

Be careful with owner and controller wording. In this local example, the filter compares effect owners, not current controllers.

Cannot Be Targeted

"Cannot be targeted" does not make a card unaffected. It only prevents effects from choosing that card as an effect target.

Toon Kingdom (c43175858.lua) protects Toon monsters from the opponent's targeting effects:

lua

local e3=Effect.CreateEffect(c)
e3:SetType(EFFECT_TYPE_FIELD)
e3:SetCode(EFFECT_CANNOT_BE_EFFECT_TARGET)
e3:SetProperty(EFFECT_FLAG_IGNORE_IMMUNE)
e3:SetRange(LOCATION_FZONE)
e3:SetTargetRange(LOCATION_MZONE,0)
e3:SetTarget(aux.TargetBoolFunction(Card.IsType,TYPE_TOON))
e3:SetValue(aux.tgoval)
c:RegisterEffect(e3)

The local helper aux.tgoval means "targeting effects controlled by the opponent." Its sibling aux.tgsval is for targeting effects controlled by the same player.

Cannot Be Destroyed

Destruction protection has two common shapes:

A simple indestructible rule with EFFECT_INDESTRUCTABLE_EFFECT.
A replacement effect such as EFFECT_DESTROY_REPLACE.

The utility helpers mirror the targeting helpers:

lua

e1:SetCode(EFFECT_INDESTRUCTABLE_EFFECT)
e1:SetValue(aux.indoval)

Use aux.indoval for opponent-controlled effects and aux.indsval for same-player effects. Use a replacement effect when the card text says to do something instead of destruction, such as banishing cards from the Deck.

What To Recheck At Resolution

Card-affecting negation effects commonly recheck:

Recheck	Example question
`tc:IsRelateToEffect(e)`	Is the targeted card still the same card this effect targeted?
`tc:IsFaceup()`	Does the effect only work on face-up monsters?
`tc:IsCanBeDisabledByEffect(e)`	Can this effect still disable the monster?
`re:GetHandler():IsRelateToEffect(re)`	Is the activating card still related to its own Chain Link?
`Duel.NegateActivation(ev)` return	Did the activation actually get negated?

Do not assume the target state from activation still exists at resolution.

Common Mistakes

Mistake	Better pattern
Using `Duel.NegateEffect` for text that says "negate the activation".	Use `Duel.NegateActivation` and gate follow-up actions behind its return value.
Registering only `EFFECT_DISABLE` for temporary monster negation.	Pair it with `EFFECT_DISABLE_EFFECT` and the correct reset.
Forgetting `Duel.NegateRelatedChain` on a target whose already-created Chain Links should be disabled.	Call it before registering the lingering disable effects.
Treating "cannot be targeted" as "unaffected".	Use `EFFECT_CANNOT_BE_EFFECT_TARGET` only for targeting protection; use `EFFECT_IMMUNE_EFFECT` for unaffected text.
Writing an immunity value function that blocks your own intended effects.	Decide whether the filter should compare owner, controller, player, type, or effect source.
Applying a temporary disable without `RESET_PHASE+PHASE_END` or another duration.	Match the reset to the card text.

Useful API pages:

Negation And Immunity ​

Choose The Correct Mechanic ​

Negating An Activation ​

Negating Only The Effect ​

Negating A Card's Effects Until A Time ​

Immunity ​

Cannot Be Targeted ​

Cannot Be Destroyed ​

What To Recheck At Resolution ​

Common Mistakes ​