Buy @ TCGplayer
When you set this scheme in motion, each opponent sacrifices a nonland permanent of their choice. If you control six or more lands, each opponent sacrifices three nonland permanents of their choice instead.
When this scheme's ability resolves, the next opponent in turn order chooses a nonland permanent (or three nonland permanents) they control to sacrifice. Then each other opponent in turn order does the same. Then all of the chosen permanents are sacrificed simultaneously. Opponents will know what choices opponents earlier in the turn order made.