During a paid ability window, only one player can act at a time. Whoever's turn it is to activate paid abilities, rez cards, and/or score agendas is said to have priority. When a paid ability window opens, priority first goes to the player whose turn it is, and that person can perform any number of these effects in any order. When that player is done acting, s/he passes priority to the other player.
|Page 21, Column 2, Paragraph(s) 5, Core Rule Book|
|Whenever there is an opportunity to trigger paid abilities, rez cards and/or score agendas (usually at the beginning of a turn and after each action), the player who is currently tracking his turn gets the first opportunity to act. He can trigger as many paid abilities, rez as many cards, and/or score as many agendas as he wishes in the order of his choosing. When he is finished, the other player gets the opportunity to act. When that player is finished, the first player gets the opportunity to act once again.|
Players continue passing priority back and forth as long as each player triggers at least one ability, rezzes at least one card, or scores at least one agenda. If someone acts, then the other player always gets priority back to respond to his/her opponent. As soon as one person declines to act, the paid ability window closes.
|Page 21, Column 2, Paragraph(s) 6, Core Rule Book|
|After both players have had at least one opportunity to act and a player declines to act, then the players cannot trigger more paid abilities, rez more cards, or score more agendas until the next opportunity to do so.|