The List

Mages' Contest

You and target spell's controller bid life. You start the bidding with a bid of 1. In turn order, each player may top the high bid. The bidding ends if the high bid stands. The high bidder loses life equal to the high bid. If you win the bidding, counter that spell.

Invasion

You and target spell's controller bid life. You start the bidding with a high bid of 1. In turn order, each player may top the high bid. The bidding ends when the high bid stands. The highest bidder loses life equal to the high bid. If you win the bidding, counter that spell.