Rules · PlanesAdvisor

101.4 If multiple players would make choices and/or take actions at the same time, the active player (the player whose turn it is) makes any choices required, then the next player in turn order (usually the player seated to the active player’s left) makes any choices required, followed by the remaining nonactive players in turn order. Then the actions happen simultaneously. This rule is often referred to as the “Active Player, Nonactive Player (APNAP) order” rule. Example: A card reads “Each player sacrifices a creature.” First, the active player chooses a creature they control. Then each of the nonactive players, in turn order, chooses a creature they control. Then all creatures chosen this way are sacrificed simultaneously.

101.4a If an effect has each player choose a card in a hidden zone, such as their hand or library, those cards may remain face down as they’re chosen. However, each player must clearly indicate which face-down card they are choosing.
101.4b A player knows the choices made by the previous players when making their choice, except as specified in 101.4a.
101.4c If a player would make more than one choice at the same time, the player makes the choices in the order specified. If no order is specified, the player chooses the order.
101.4d If a choice made by a nonactive player causes the active player, or a different nonactive player earlier in the turn order, to have to make a choice, APNAP order is restarted for all outstanding choices.
101.4e If multiple players would make choices or take actions while starting the game, the starting player is considered the active player and each other player is considered a nonactive player.