Each player chooses any number of creatures they control with total power 4 or less, then sacrifices all other creatures they control.
1/19/2018 Slaughter the Strong has each player choose any number of creatures and then checks that the total power of creatures each player chose this way is 4 or less. For example, you could save two 2/2 creatures, or a 1/1 and a 3/3 creature, but not all four of those creatures.
1/19/2018 If a creature’s power is somehow less than 0, it subtracts from the total power of the other creatures its controller chooses. This can cause creatures with power 5 or greater to survive.
1/19/2018 Starting with the player whose turn it is, each player in turn order chooses the appropriate number of creatures. Then the remaining creatures are sacrificed simultaneously. Players will know choices made by earlier players when making their choices.