Rules explained

Priority

Priority is the right to take discretionary actions, such as playing a card or activating an ability, and only one player can have it at a time. On your turn, you have Priority in your Main Phase whenever no Showdown or combat is in progress and no chain exists, which is when most cards get played.

Once a spell or ability is on the chain, Priority moves between the players. The player who controls the newest item on the chain gets Priority first and can add a Reaction or pass, and then the next player gets the same choice. When every player has passed in a row without adding anything, the newest item resolves, and if anything is still on the chain, its controller gets Priority again.

Focus

Focus only exists during a Showdown, and like Priority, only one player can have it at a time. It is the permission to take discretionary actions while the Showdown is open, which means no chain is waiting to resolve. The player who contested the battlefield gains Focus as the Showdown begins, and when a Showdown opens as part of combat, that player is the attacker. A player who gains Focus also gains Priority.

With Focus, you can play a card or activate an ability that is legally timed, which during a Showdown means one with Action or Reaction, or you can pass.

How they work together

Focus decides who gets to start the next play in a Showdown, and Priority decides who can respond once something is on the chain. When the player with Focus plays a spell, it starts a chain, and Priority moves between the players as usual so each of them can answer with a Reaction. Passing Priority during that chain does not give up Focus, and a player cannot act with Focus unless they also have Priority.

When the last item on that chain resolves and the Showdown is open again, Focus passes to the next player in turn order, who also gets Priority. The exception is a chain that a triggered ability or an Add ability started, such as the Combat Chain that triggered abilities open at the start of combat: when that chain finishes, Focus stays where it was.

When the Showdown ends

If the player with Focus passes instead of playing something, Focus moves to the next player in turn order. Once every player has passed in a row without playing a card or activating an ability, the Showdown closes. In combat, the remaining combat steps follow, and if both attacking and defending units are still at the battlefield, combat damage is resolved. In a Showdown without combat, a player whose units are the only ones left there takes control of the battlefield if they did not already control it, which is a conquer if they have not scored that battlefield this turn.

A combat, step by step

Say you move a unit to a battlefield where your opponent has units. A Showdown opens as part of combat, you are the attacker, and you gain Focus and Priority. If any abilities trigger as combat starts, they go on the chain and resolve first, and Focus stays with you afterward.

You then play an Action spell, and after you pass Priority, your opponent answers with a Reaction. If nobody adds anything else, the Reaction resolves first and then your spell does, and with the chain empty, Focus passes to your opponent. They can play an Action or Reaction card or pass, and once both of you pass in a row, the Showdown closes and combat damage follows if both sides still have units there.