The Secrets of Missed Triggers in Magic: The Gathering

Abhi Vaidyanatha
6 min readMar 26, 2024


Last Friday, a shop regular was doing some reading on missed triggers and came up with a question for me that resembles the following:

Active player has a Monastery Swiftspear on board and casts a Lightning Bolt targeting the Non-active Player in their Main Phase 1. They don’t announce the Prowess trigger of the Monastery Swiftspear. When they go to combat, at the Beginning of Combat Step, the Non-Active player asks the Active player, “What is the power and toughness of the Monastery Swiftspear?” Active player refuses to answer and a judge is called. How do you rule?

To properly answer this judge call, we’ll need to determine two things that you should also be on the lookout for as a player in this situation:

  1. Was the Prowess trigger missed?
  2. Does the Non-active player have open access to the information they asked for?

The Prowess Trigger

First, let’s consult the comprehensive rules on Prowess, which says:

702.107a Prowess is a triggered ability. “Prowess” means “Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.”

According to the CR, we have confirmed that Prowess is indeed a triggered ability, which means that it can absolutely be missed. The question now is, has it been missed here? I’ll bet that on average, most players would say that it has been missed since it wasn’t declared on the Lightning Bolt cast. However, one quick look at the rules for Missed Trigger clearly say otherwise. Consider the relevant part of the IPG (Infraction Procedure Guide) here:

Missed Trigger Definition: A triggered ability triggers, but the player controlling the ability doesn’t demonstrate awareness of the trigger’s existence by the first time that it would affect the game in a visible fashion.

Now, what does it mean to affect the game in a visible fashion? Triggered abilities are split into four general groups:

  1. Abilities that target
  2. Abilities that cause a visible change in the game state (life totals changing, creating a token, etc.)
  3. Abilities that change the rules of the game
  4. Abilities that affect the game state in generally non-recordable, non-visible ways

Prowess, weirdly enough, fits into the fourth group. It doesn’t visibly affect the game state, because players are never representing it with a die on a creature (it would be very confusing with +1/+1 counters) and generally just remember how many prowess triggers they have. Some players have a separate die to track it, like for Storm count, but it’s not required for them to do so. So, generally, the first time it would affect the game in a visible fashion would be the first time the creature deals damage or is dealt damage. And therefore, the acknowledgement of the trigger must only be announced in the Damage Step of combat, or if it were targeted by a damage or toughness-based removal spell, which ever comes first. So the trigger has not been missed yet.

The philosophy of the rule is baked into the fact that Magic is not played with perfect technical communication. Players aren’t Yu-Gi-Oh anime duelists who announce every part of a spell or ability’s resolution. As long as it is tracked and acknowledged when relevant, it’s not missed.

Most competitive players are aware of this, as Monastery Swiftspear is an incredibly common card in nearly every format. In fact, it is legal in every single constructed format as of this post’s publishing date, except Pauper, in which it was just recently banned. But for exclusive Limited-format players, this may be a surprise when playing with Prowess, or similar triggered abilities.

What information do you have access to?

The second part of this question lies in what type of information the current Power and Toughness of a creature is, and whether the Non-Active player has innate access to it. The four types of information as per the MTR are:

  1. Status (life totals, counters, who the monarch is, etc.)
  2. Free (what phase it is, game score, relevant game actions)
  3. Derived (hand size, graveyard size, changes to game rules)
  4. Private (everything else, hidden zones)

Types 1 and 2 are freely available to both players at any given time. In the spirit of efficient communication, if your opponent asks you about anything in these two categories, you should respond honestly and quickly. However, Types 3 and 4 are not like this at Competitive REL. In fact, you are allowed to freely lie about Type 4, or Private information. Type 3, or Derived information, you are not allowed to lie about, but you don’t have to give to your opponent. At Regular REL, which all FNM-style events generally are, Type 3 is considered Type 2, and therefore must be provided by your opponent.

The Power and Toughness of a creature is in fact, derived information, as it is non-visible information about the game state that is a result of game actions. However, the key observation here should be that it’s a result of game actions. Therefore, the Non-Active player has access to the information of all relevant game actions that the Active player has taken this turn. Active player, therefore, must say to the Judge, “I have cast Lightning Bolt earlier this turn,” (or something to that effect) which Non-Active player can use to infer the P/T of Monastery Swiftspear.

Most tournament-goers, honestly, will just tell you the P/T. It’s a really small advantage that relies on being somewhat obtuse and preys on newer players that don’t understand rules minutiae. But that sets up one last issue.

The Secret Third Way to Miss the Trigger

Finally, there’s a small, and relevant trap here for the Active Player. I mentioned earlier that there’s two ways to miss the trigger:

… the acknowledgement of the trigger must only be announced in the Damage Step of combat, or if it were targeted by a damage or toughness-based removal spell, which ever comes first.

There is in fact a third way, and it’s probably the best reason that people may not answer the P/T question. Let’s slightly change the initial situation in this article to play out like this:

… When they go to combat, at the Beginning of Combat Step, the Non-Active player asks the Active player, “What is the power and toughness of the Monastery Swiftspear?” Active player says, “It’s a 1/2.”

In this scenario, since the Active player said it’s a 1/2, that meets the requirements for Missed Trigger, as the player did not demonstrate awareness of the trigger the first time it would affect the game, which includes relaying information to your opponent. As I mentioned above, you’re not allowed to lie about derived information, so this indicates that the trigger was missed.

If the Active player tries to go on to claim it’s a 2/3 during the Combat Step because they meant base power and toughness 1/2 when they said “1/2,” I would likely rule in favor of the Non-Active player after conducting a short investigation to make sure that the Active player did actually misrepresent the game state earlier. If this had come up before during the day with the same player, I would do a Cheating investigation here too, as you’re not allowed to intentionally misrepresent game state.


First off, don’t let players claim that you missed your Prowess, Battle cry, or similar triggers if you didn’t announce it before it was relevant to the game state. Also, make sure to call a Judge if someone is not providing information to you, or has misrepresented information, especially at Regular REL where the focus is on gameplay experience. If you are an experienced player playing at Regular REL, I recommend clarifying the game state proactively by volunteering derived information to newer players if they are displaying any confusion, as it is considered Free information at the lower rules enforcement level.