Can a player play a reaction card (Defy) that they draw mid-chain resolution from another card effect (Discipline), or must they wait until the entire chain finishes resolving?

Ruling: Players can play reactions during chain resolution, not just before it starts. After each chain item resolves, if more items remain on the chain, priority goes to the controller of the next chain item, and both players can add new reactions before the next item resolves.

Sequence:

• Chain is built with all initial actions/reactions
• Players pass priority and the top chain item begins resolving
• After it resolves, if more items remain, priority goes to the controller of the next chain item
• Both players can now play reactions before the next item resolves
• This continues until the chain is empty

Nuances:

• This differs from games like Yu-Gi-Oh where chains must fully resolve once they begin
• If a player draws a reaction card mid-chain (like from Discipline), they can play it when they receive priority
• Priority alternates based on who controls the next pending chain item