Board wipes are mass-removal effects designed to clear multiple permanents at once rather than trading with them individually. Creature wipes are the most common, although some cards can sweep away artifacts, enchantments, graveyards, or several permanent types simultaneously.
The original creature board wipe, Wrath of God, destroys all creatures without fear of regenerating, Toxic Deluge shrinks an entire creature board, and the game-changer Farewell selectively exiles creatures, artifacts, enchantments, and graveyards.
