Archenemy is a casual, multiplayer, "one vs. many" format. One player chooses to play as the villain, while the rest form a team against that player. The villain receives several advantages, including a higher starting life and a deck of special scheme cards, and always plays first. The team opposing the archenemy shares a turn, as in Two-Headed Giant, and its players can block for each other.
The format was designed with a focus on emotional response, rather than mechanics. The archenemy role led to "infectious" role-play during playtesting, and the scheme cards were given names and flavor text to enhance that experience.
Archenemy was introduced in the product of the same name in 2010. The second installment, Archenemy: Nicol Bolas, was released on June 16, 2017.