How does action/reaction timing work during combat, specifically regarding who can cast reactions first and when buffs apply?

Ruling: The attacker has priority to add to the chain first during combat. Players alternate adding reactions to the chain, which resolve in reverse order (last in, first out). If both players pass consecutively, combat resolves and no more reactions can be added.

Sequence:

• Attacker has priority and can play a reaction first or pass
• Defender can respond with their own reaction or pass
• Players continue alternating until both pass consecutively
• Once both players pass, the chain resolves in reverse order (last played resolves first)
• A player can "hold priority" and play multiple reactions in a row, but opponent gets a window to respond between each card

Nuances:

• Reactions can be played before moving units during an attack (pre-combat)
• If a reaction is played before movement, opponent can only respond with reactions (not actions)
• Some reactions have targeting conditions (like requiring units to be at a battlefield) that may prevent them from being played at certain times
• Strategic passing can allow you to respond to opponent's reactions by letting them act first