How does priority and focus work during showdown, particularly: (1) Does priority auto-pass after an action resolves? (2) Does the attacker keep priority after playing a reaction? (3) How does the initial chain from attack/defend abilities work?

Ruling: The attacker has focus during showdown, which grants them priority and allows them to play actions. After a chain fully resolves, focus passes automatically to the defender. When playing reactions, you may continue playing reactions until you choose to pass priority.

Sequence:

• Showdown starts with attacker having focus
• If attack or defend abilities exist, they create an Initial Chain that must fully resolve first
• After the Initial Chain resolves (or if there isn't one), the attacker gains focus
• The attacker can play an action, which starts a chain
• Players can add reactions to the chain until both pass priority
• After the chain fully resolves, focus passes automatically
• The player with focus can then play another action

Nuances:

• Assault and Shield are passive abilities, not attack/defend abilities, so they don't create an Initial Chain
• You can play reactions to triggers on the Initial Chain
• As items resolve on a chain, each link can be reacted to before it resolves
• You cannot stack two actions in the same chain
• After an item resolves on the chain, before the next item resolves, players can add reactions