801.1. Limited range of influence is an option that can be applied to most multiplayer games. It’s always used in the Emperor variant (see rule 809), and it’s often used for games involving five or more players.
801.2. A player’s range of influence is the maximum distance from that player, measured in player seats, that the player can affect. Players within that many seats of the player are within that player’s range of influence. Objects controlled by players within a player’s range of influence are also within that player’s range of influence. Range of influence covers spells, abilities, effects, damage dealing, attacking, making choices, and winning the game.
801.2a The most commonly chosen limited ranges of influence are 1 seat and 2 seats. Different players may have different ranges of influence.
801.2b A player is always within their own range of influence.
801.2c The particular players within each player’s range of influence are determined as each turn begins.
801.2d An object is within a player’s range of influence if it’s controlled by that player or by another player within that many seats of that player.
801.3. Creatures can attack only opponents within their controller’s range of influence or planeswalkers controlled by those opponents. If no opponents are within a player’s range of influence, creatures that player controls can’t attack.
801.4. Objects and players outside a player’s range of influence can’t be the targets of spells or abilities that player controls.
801.5. Some cards require players to make choices. These cards work differently when the limited range of influence option is used.
801.5a If a player is asked to choose an object or player, they must choose one within their range of influence.
801.5b If a player is asked to choose between one or more options (and not between one or more objects or players), they can choose between those options even if those options refer to objects or players outside the player’s range of influence.
801.5c If an effect requires a choice and there’s no player who can make that choice within its controller’s range of influence, the closest appropriate player to its controller’s left makes that choice.
801.6. A player can’t activate the activated abilities of an object outside of their range of influence.
801.7. A triggered ability doesn’t trigger unless its trigger event happens entirely within the range of influence of its source’s controller.
801.7a If a trigger event includes an object moving out of or into a player’s range of influence, use the game state before or after the event as appropriate to determine whether the triggered ability will trigger. See rules 603.6 and 603.10.
801.8. An Aura can’t enchant an object or player outside its controller’s range of influence. If an Aura is attached to an illegal object or player, the Aura is put into its owner’s graveyard as a state-based action. See rule 704.
801.9. An Equipment can’t equip an object outside its controller’s range of influence, and a Fortification can’t fortify an object outside its controller’s range of influence. If an Equipment or Fortification is attached to an illegal permanent, it becomes unattached from that permanent but remains on the battlefield. This is a state-based action. See rule 704.
801.10. Spells and abilities can’t affect objects or players outside their controller’s range of influence. The parts of the effect that attempt to affect an out-of-range object or player will do nothing. The rest of the effect will work normally.
801.11. If a spell or ability requires information from the game, it gets only information from within its controller’s range of influence. It doesn’t see objects or events outside its controller’s range of influence.
801.12. The “world rule” (see rule 704.5k) applies to a permanent only if other world permanents are within its controller’s range of influence.
801.13. Replacement and prevention effects watch for a particular event to happen and then completely or partially replace that event. The limited range of influence option can cause the modified event to contain instructions that can’t be carried out, in which case the player simply ignores the impossible instructions. See rule 614, “Replacement Effects,” and rule 615, “Prevention Effects.”
801.13a If a replacement effect tries to cause a spell or ability to affect an object or player outside its controller’s range of influence, that portion of the event does nothing.
801.13b If a spell or ability creates an effect that prevents damage that would be dealt by a source, it can affect only sources within the spell or ability’s controller’s range of influence. If a spell or ability creates an effect that prevents damage that would be dealt to a permanent or player, it can affect only permanents and players within the spell or ability’s controller’s range of influence. If a spell or ability creates an effect that prevents damage, but neither the source nor the would-be recipient of the damage is specified, it prevents damage only if both the source and recipient of that damage are within the spell or ability’s controller’s range of influence.
801.14. If an effect states that a player wins the game, all of that player’s opponents within that player’s range of influence lose the game instead.
801.15. If the effect of a spell or ability states that the game is a draw, the game is a draw for that spell or ability’s controller and all players within that player’s range of influence. They leave the game. All remaining players continue to play the game.
801.16. If the game somehow enters a “loop” of mandatory actions, repeating a sequence of events with no way to stop, the game is a draw for each player who controls an object that’s involved in that loop, as well as for each player within the range of influence of any of those players. They leave the game. All remaining players continue to play the game.
801.17. Effects that restart the game (see rule 719) are exempt from the limited range of influence option. All players in the game will be involved in the new game.
801.18. In multiplayer Planechase games other than Grand Melee games, plane cards and phenomenon cards are exempt from the limited range of influence option. Their abilities, and the effects of those abilities, affect all applicable objects and players in the game. See rule 901, “Planechase.”