Demystifying Rulings, Part 3: SEGOC

[Stardog]

Trigger effects come up all of the time in Yu-Gi-Oh!, and there are a couple of simple game mechanics that govern how they work.


This article will assume you’re familiar with Chains. If they aren’t, or you want to quickly refresh your memory, check out the rulebook: [You must be registered and logged in to see this link.]



Trigger effects always activate after the current chain (if any) resolves.

Let’s see an example. Suppose Atlantean Marksman and Mermail Abyssgunde are discarded by the effect of Mermail Abyssmegalo as a cost.
When this card is sent to the Graveyard to activate a WATER monster’s effect: Target 1 Set card your opponent controls; destroy that target.

If this card is discarded to the Graveyard: You can target 1 “Mermail” monster in your Graveyard, except “Mermail Abyssgunde”; Special Summon that target. You can only use the effect of “Mermail Abyssgunde” once per turn.

You can discard 2 other WATER monsters to the Graveyard; Special Summon this card from your hand. When you do: You can add 1 “Abyss-” Spell/Trap Card from your Deck to your hand. You can Tribute 1 other face-up Attack Position WATER monster; this card can make a second attack during each Battle Phase that turn.

Chain Link 1: Megalo’s effect to Special Summon, discarding Marksman and Gunde (note that Megalo’s effect does indeed start a chain – its effect has a semi-colon).

The effects of Marksman and Gunde do not activate yet, even though they’ve technically met their activation condition. They wait for the Chain to resolve before activating.

Resolve Chain: Megalo is Special Summoned.

At this point, we look at what effects have been triggered and want to activate. Marksman and Gunde have been waiting, and at this point Megalo’s second effect has also been triggered.

This situation, where we have multiple trigger effects wanting to activate, is called SEGOC: Simultaneous Effects Go On Chain.

(Note: ‘Missing Timing’ (or ‘when vs if’ on optional effects) will be explained in the next article, and there’ll be no need to worry about it in this one.)

When multiple trigger effects want to activate at the same time, they do so in the following order:

TP mandatory
NTP mandatory
TP optional
NTP optional
(where TP stands for Turn Player and NTP stands for Non-Turn Player).
In addition, if there are multiple effects in a category, the ones meeting their activation condition strictly earlier must go earlier on the chain (in the TCG – in the OCG, this rule doesn’t exist). If they’re triggered by exactly the same thing, then the effects can go in any order.



As usual, let’s immediately see this in action:

Player A controls Dante, Traveler of the Burning Abyss, with Cir, Malebranche of the Burning Abyss as Xyz Material. Player B controls Shaddoll Beast. It’s Player A’s turn, and he activates Dark Hole.
If this card is sent to the Graveyard: You can target 1 “Burning Abyss” card in your Graveyard, except this card; add it to your hand.

If this card is sent to the Graveyard: You can target 1 “Burning Abyss” monster in your Graveyard, except “Cir, Malebranche of the Burning Abyss”; Special Summon it.

If this card is sent to the Graveyard by a card effect: You can draw 1 card.

Chain Link 1: Dark Hole

Resolve: Dark Hole destroys Dante and Beast, and Cir is also sent to the Graveyard, all of this at the same time.

Dante and Cir are both the TP’s (optional) effects, and both met their activation conditions at the same time. So they go on the Chain first as CL1 and CL2 in either order (owner’s choice). Beast is the NTP’s (optional) effect, so it must be after them at CL3.

Chain Link 1 and Chain Link 2: Dante and Cir (either order)
Chain Link 3: Beast.



Let’s next look back at that Marksman/Gunde/Megalo example:
When this card is sent to the Graveyard to activate a WATER monster’s effect: Target 1 Set card your opponent controls; destroy that target.

If this card is discarded to the Graveyard: You can target 1 “Mermail” monster in your Graveyard, except “Mermail Abyssgunde”; Special Summon that target. You can only use the effect of “Mermail Abyssgunde” once per turn.

You can discard 2 other WATER monsters to the Graveyard; Special Summon this card from your hand. When you do: You can add 1 “Abyss-” Spell/Trap Card from your Deck to your hand. You can Tribute 1 other face-up Attack Position WATER monster; this card can make a second attack during each Battle Phase that turn.

Chain Link 1: Megalo’s effect to Special Summon, discarding Marksman and Gunde

Resolve: Megalo SSes itself.

Marksman, Gunde, and Megalo have all met their activation conditions. Marksman is TP mandatory, so it goes first. Gunde and Megalo are both TP optional, but Gunde met its activation condition strictly earlier, so it must be Chain Link 2 before Megalo.

Chain Link 1: Marksman, targeting a Set card
Chain Link 2: Gunde, targeting a Mermail in the Graveyard
Chain Link 3: Megalo’s second effect.

I’ve laid out the Chains fully in the above examples because it’s good practice to properly build them and then resolve them carefully.

Miscellaneous Points
After all trigger effects go on the Chain, only then can the players Chain with fast effects. Even Counter Traps cannot be used while the trigger effects are all still being put on the Chain. This is important because, in order to negate activations of effects, you need to Chain directly to that activation.

Some Spell and Trap Cards have effects that activate when a condition is met, while the Spell/Trap is face-up. These effects are called Trigger-Like, and they function just like Trigger effects do. So, for example, they will also follow the rules of SEGOC.

A good example of this is type of effect is (the second effect of) Vanity’s Emptiness:
Neither player can Special Summon monsters. If a card is sent from the Deck or the field to your Graveyard: Destroy this card.

Now for some warnings:

1) SEGOC does not apply to effects activating during a particular Phase or Step (like, eg, the Standby Phase or the End Step of the Battle Phase). Those activate and resolve in separate Chains.

For example, suppose you have two Lyla, Lightsworn Sorceress face-up
During each of your End Phases: Send the top 3 cards of your Deck to the Graveyard.

The Lylas’ effects do not form a Chain in the End Phase. They activate and resolve separately.

2) There is a single exception to the rule of SEGOC. Roughly speaking, you cannot activate multiple trigger effects that involve Special Summoning from the hand (or trigger effects activating in the hand that Special Summon period). For example, you cannot activate 1 Gorz, Emissary of Darkness and 1 Tragoedia in response to taking damage, even though under the normal law of SEGOC, both cards would activate in a Chain.
When you take damage from a card in your opponent’s possession: You can Special Summon this card from your hand.

When you take Battle Damage: You can Special Summon this card from your hand.