If both players declare no action during a Showdown, can the attacker then play a spell at reaction speed, or does combat proceed directly to damage distribution?

Ruling: If both players pass on actions/reactions during a Showdown, combat proceeds directly to the damage step. You cannot play a spell at reaction speed after both players have passed.

Sequence:

• Attacker declares action or passes
• Defender declares action or passes
• If both pass, proceed immediately to damage distribution
• No additional opportunity to play spells at reaction speed