Hello judges, and welcome to another bound of the Knowledge Pool! This week's scenario is Silver, so L2 judges will need to wait until Friday before contributing to the discussion.

You're the head and only judge at a limited GPT.

Amy is playing against Neil, and controls Dragonlord Atarka and Surrak, the Hunt Caller. As Amy is about to enter her combat phase, Neil casts Ojutai's Breath on her Dragonlord Atarka, placing the spell sideways beside his graveyard. Amy thinks for a bit and decides not to attack with her Surrak and passes the turn.

Neil draws for his turn and proceeds to attack with his Shu Yun, the Silent Tempest As Amy is about to block, Neil realizes his Ojutai's Breath is still in exile, and calls you over. What do you do?

The initial casting of Ojutai's Breath appears to have been done correctly - Neil has placed Ojutai's Breath in exile, and consequently there's no GPE here.

The wording of Rebound is such that the player “may” cast it at the beginning of the next upkeep. This is a delayed triggered ability that was missed when Neil proceeded to draw for his turn.
This is clearly not a detrimental trigger, and so we have a GPE-MT with no warning. Amy chooses whether the trigged ability (You may cast ~ without paying its mana cost) is put on the stack, otherwise play continues.
If Ojutai's Breath is not cast, it remains in exile, and doesn't trigger again in following turns.

The rebound ability creates a delayed trigger upon resolving sucessfully, therefore it is a missed trigger during the upkeep step.

The missed trigger is not detrimental, so no warning will be given for this missed trigger.

As the trigger is still caught within a turn (combat phase to combat phase), Amy can choose whether to put it on the stack or not.

If she doesn't choose to put it on the stack, the card remains exiled.
If she does the spell is casted next time a player gets priority.

This is a Missed Trigger for Neil. It's not a detrimental trigger so no penalty. Since the trigger “creates an effect whose duration has already expired” I just instruct the players to keep playing and the card will remain in exile indefinitly.

After reading responses :
Yeah, read a bit on the Missed Trigger guide and yes we should ask the opponent if she wants to put it on the stack. Since she does not, the spell will stay in exile indefinitly :)

Edited Jaurès Chabalier (May 29, 2015 08:50:24 AM)

The rebound ability on Ojutai's Breath creates a delayed triggered ability “At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.” By drawing for the turn and attacking, Neil has clearly moved past his upkeep, and missed his trigger. He won't get a warning because the trigger is not generally detrimental. It was caught within a turn cycle, so we will ask Amy if she wants to put the rebound trigger onto the stack (to which she will probably say no).

One potential sticking point is that rebound sort of looks like a delayed triggered ability that causes an object to change zones, which would mean that Amy would have the choice to either resolve it immediately or at the beginning of the next phase. But rebound doesn't actually change the zone of the object. All it does is allow you to cast the spell from exile, which then causes it to go to the graveyard.

So what we have here is a player who has either forgotten to rebound his spell or chosen not to. Since the delayed triggered rebound ability has a may clause, it is assumed that Neil has chosen not to cast the spell.

This means that there is no infraction and no penalty. Since the card was not cast and rebound gives no instructions on what to do if the exiled spell is not cast, the spell remains in exile.

Before:
The trigger on Ojutai's Breath is a may ability, as such it is assumed Neil chose not to cast it. As such it remains exiled and the game continues. No infractions are awarded.

After:
It appears that even if it is a may, the opponent still choses to put it on the stack or not. Now I know :D.

Edited Kai Clark (May 29, 2015 11:22:37 PM)

A missed trigger that is non-detrimental (so no warning) for Neil, Amy may choose to add it to the stack, if so we add it to the bottom of the stack and play continues.

The interesting trip up points seem to be:

Mistaking this for a zone changing trigger, which it isn't as it simply allows casting and that would cause the zone change (as noted by Dave)

The suggestion that a ‘may’ clause has a default option, which it doesn't. May requests a choice, the phrase you need to see for a default option is ‘if you don’t…'

Hello Judges! This week's discussion went quite nicely, touching on all the points we wanted to make with this scenario.

Everyone quickly identified that Neil had committed a GPE - Missed Trigger and would not be getting a Warning for it, as a triggered ability that lets you cast a spell for free is not considered generally detrimental. What's more, any trigger that gives its controller the option not to do anything is never considered generally detrimental as, after all, there is the option not to do anything.

Now, regarding the fix, two very important points were made:

• Though rebound does create a delayed triggered ability, this ability does not cause a zone change; it merely lets you cast your spell. This means we can't just resolve it immediately.
  
  
• If you look closely, you'll notice that the IPG does not say anything about how to deal with “optional” triggered abilities or those that include “may” in their wording; it only mentions what to do with triggers that have a default option. These latter ones are worded to include phrases like “Do X. If you can't/don't, do Y” or “Unless you do X, do Y.” As such, we cannot assume that Neil chose the “default” option to not cast his spell because there is none.
  

So, we go back to the old trusty “Amy, do you want to place Neil's trigger at the bottom of the stack?” If she decides to do so, Neil may decide whether or not to cast his Ojutai's Breath.

Thanks again for your discussion. Until next time!