Is Annie's Dark Child effect mandatory, and what happens if you forget to ready up to 2 runes during your End phase?

Ruling: Annie's effect is mandatory and must be resolved during your End phase. If you miss the trigger and notice it in a later turn phase, it is a missed trigger and you continue playing without the extra runes.

Sequence:

• If you pass turn and immediately remember before opponent awakens, you can still resolve it
• Once opponent has awakened or taken actions, the trigger is missed
• At competitive REL, stricter enforcement (no resolution after passing)
• At casual events like Nexus Night, more leniency may be given for rewinding

Nuances:

• "Up to 2 runes" means you choose 0-2, so the trigger is mandatory but the number is a choice
• Whether an effect says "may" or not is irrelevant to Riftbound's missed trigger policy
• Intentionally not readying runes and then trying to use them could be considered angle shooting and result in disqualification