When can I play a hidden card after I play Discipline?

Ruling: You can play a Hidden card immediately after playing Discipline while still holding priority, without waiting for Discipline to resolve.

Sequence:

• You have priority and play Discipline, which is added to the chain as a Pending Item
• While still holding priority, you can play another legally timed card (like a Hidden card with the Reaction tag)
• You play your Hidden card, which is added to the chain on top of Discipline
• You then pass priority to your opponent
• During resolution (LIFO), the Hidden card resolves first, then Discipline resolves (granting +2 might and drawing a card)

Nuances:

• Hidden cards gain the Reaction tag, allowing them to be played during reaction windows
• You can only play a card from the Hidden state if it was placed there on a previous turn, not the card you just drew
• If the Hidden card is a permanent (Unit or Gear), it bypasses the resolution step and finalizes immediately, but the priority window still applies