Union Arena Trigger System Explained: All Trigger Types

How we checked this: we read the trigger sections of Bandai's Official Rule Manual and Tournament Rules Manual, checked each trigger's wording on official English card list entries from five colors, and counted the triggers in the list that won Core TCG's regional with a script.

Updated October 16, 2026: We replaced the generic descriptions with the exact standard text of every trigger, fixed Color (the effect is set by the card's color, not by the card), and added the trigger count of a real regional-winning deck.

How a Union Arena trigger fires

The rule manual's sequence, step by step:

1. Damage. An attack that isn't blocked deals 1 damage, or 2 with Damage 2.
2. The attacker picks. "The player dealing damage selects one card in the damaged player's life area for each point of damage dealt."
3. Flip and decide. Turn each card face up. If it has a trigger, you may activate it. It's optional.
4. Sideline. The card goes to your sideline after the trigger resolves, and cards without triggers go there too, unless the trigger moved it somewhere else.
5. Several cards. With more than one trigger, you choose the order, and each one is activated, resolved and sidelined before the next.
6. Game check. Only after every trigger is done: if the defender has no life left, the attacker wins.

You start with seven life cards taken from the top of your deck, so your triggers are whatever your deck is made of. It also means the player who has lost more life has flipped more triggers.

Every trigger type, word for word

Within a type, the wording was identical on every card we checked. These are the texts on Bandai's English card list:

Get and Raid are the two that change where the card goes: Get puts the flipped card in your hand, and Raid can put it straight onto your field on top of a character with the same name. The Raid guide covers that part.

Special is the strongest of the standard texts: it sidelines any front-line character, with no BP limit. Boogie Woogie carries it in the Jujutsu Kaisen deck below.

Image: Bandai, UNION ARENA official card list

Final only works on the hit that empties your life area. It puts one card back, and since the loss check waits until every trigger has resolved, your opponent needs another point of damage to finish.

Color triggers by color

Color is the trigger people get wrong, because the effect isn't printed per card. It depends on the color:

Image: Bandai, UNION ARENA official card list

Joseph Writer Anderson ranked them and put Yellow on top, calling it "so strong you could even say it's broken compared to the other Color Triggers." Green came last for a practical reason: "you tend to not have any targets for this particular color trigger when it activates," because Green decks lean on big characters.

The four-copy cap

The Tournament Rules Manual is short on it: "Cards with the Special, Color, and Final triggers are limited to no more than 4 cards in a deck for each trigger type." It counts cards, not card names. Two different Special cards share the same four slots, so a deck can't hold more than twelve capped triggers in total.

What a winning deck's triggers look like

Here's the Purple Jujutsu Kaisen list that won Core TCG's regional, dated July 31, 2026, sorted by trigger:

Two things stand out. Only three of the 50 cards have no trigger, and the list runs exactly four of each capped type. There's an 87.4% chance that at least one of its seven life cards is a Special, Color or Final. If you're attacking into this deck, assume you'll hit one.

Bandai's own rules tutorial shows a trigger check on the table if you'd rather see it played out:

Playing around triggers

• Count the capped ones. Each Special, Color or Final your opponent has already flipped or played is one fewer left in their life area and deck. Late in the game that number tells you how risky the next swing is.
• The last point is the dangerous one. A Final trigger fires on any hit that leaves the defender at 0 life, including a Damage 2 hit that takes their last two cards at once; Bandai's FAQ confirms it still activates. If both of those cards are Final, only the first one resolves. Plan for one more point of damage than they have life.
• Respect Special with your best character. Special sidelines anything on the front line, so the swing that flips it can lose you your biggest body on the way.
• Yellow and Blue punish small boards. Against those colors, a front line of cheap characters is exactly what their Color trigger hits.

Our take

The Union Arena trigger system isn't luck you ignore; it's a second hand your opponent hasn't drawn yet. Run your four of each capped type unless a card is genuinely bad, and when you attack, think about what a flip does to you, not just what the hit does to them.

Frequently Asked Questions

How do triggers work? The player dealing damage picks a life card per point of damage. Each is flipped, you may use its trigger, and it then goes to your sideline unless the trigger moved it.

What are the trigger types? Get, Draw, Active, Raid, Special, Color and Final, plus no trigger. Special, Color and Final are capped at four cards each.

What does a Color trigger do? It depends on the card's color: Red and Blue remove small characters, Yellow rests one, Purple and Green play a small character for free.

What is a Final trigger? If you have 0 life, it puts the top card of your deck into your life area.

Can you build around triggers? You build with them. Core TCG's winning list has a trigger on 47 of 50 cards and maxes all three capped types.

Do you have to use a trigger? No, it's optional. The card goes to the sideline either way.

Related Reading

• Union Arena Purple Todo Deck Guide: the winning list used above.
• Union Arena Impact Keyword Explained: Impact and Damage, the keywords that decide how many life cards get flipped.
• Union Arena Beginner Mistakes: 8 Errors to Stop Making: common rules slips.
• Union Arena Keywords Glossary: every keyword in one place.