601.2d 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.

601.3. Creatures can attack only opponents within their controller’s range of influence. If no opponents are within a player’s range of influence, creatures that player controls can’t attack.

601.4. Objects and players outside a player’s range of influence can’t be the targets of spells or abilities that player controls.

601.5. Some cards require players to make choices. These cards work differently when the limited range of influence option is used.

601.5a If a player is asked to choose an object or player, he or she must choose one within his or her range of influence.

Example: In a game with a range of influence of 1, Alex is seated to the left of Rob. Alex activates the ability of Cuombajj Witches, which reads, “Cuombajj Witches deals 1 damage to target creature or player and 1 damage to target creature or player of an opponent’s choice,” targeting Rob and choosing Rob as the opponent who picks the other target. Rob must choose a target that’s in both his range of influence and in the range of influence of the controller of Cuombajj Witches. He must therefore choose himself, Alex, or a creature controlled by either himself or Alex.

601.5b If a player is asked to choose between one or more options (and not between one or more objects or players), he or she can choose between those options even if those options refer to objects or players outside the player’s range of influence.

Example: Alex, who has a range of influence of 2, is seated to the left of Rob, and Carissa, who has range of influence of 1, is seated to the right of Rob. Alex plays a card that reads, “An opponent chooses one – You draw 2 cards; or each creature you control gets +2/+2 until end of turn,” and chooses Carissa to make that choice. Carissa can choose the mode even though Alex is out of her range.

601.5c 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.

Example: In an Emperor game in which all players have range of influence 1, an emperor plays Fact or Fiction, which reads, “Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.” Since no opponent is within the emperor’s range of influence, the nearest opponent to the emperor’s left separates the cards into piles.

601.6. A player can’t play the activated abilities of an object outside of his or her range of influence.

601.7. A triggered ability doesn’t trigger unless its trigger event happens entirely within the range of influence of its source’s controller.

Example: In a game with range of influence limited to 1, Alex is seated to the left of Rob. Rob controls two Auras attached to Alex’s Grizzly Bears: One with the trigger condition “Whenever enchanted creature becomes blocked,” and one with the trigger condition “Whenever enchanted creature becomes blocked by a creature.” Alex’s Grizzly Bears attacks the player to Alex’s left and becomes blocked. The ability of Rob’s first Aura triggers because the entire event (Grizzly Bears becomes blocked) happens within Rob’s range of influence. The ability of Rob’s second Aura doesn’t trigger, however, because that event includes the blocking creature, which is out of Rob’s range.

601.7a 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 rule 410.10.

Example: Carissa and Alex are outside each other’s range of influence. Carissa controls a creature owned by Alex and they each control a Soul Net, an artifact which reads, “Whenever a creature is put into a graveyard from play, you may pay {1}. If you do, you gain 1 life.” The creature is destroyed and is put into Alex’s graveyard. Alex’s Soul Net doesn’t trigger because the destruction event was outside Alex’s range of influence. Carissa’s Soul Net does trigger, even though the creature is going to a graveyard outside her range, because the destruction event was within her range.

601.8. An Aura can’t enchant an object outside its controller’s range of influence. If an Aura is attached to an illegal permanent, the Aura is put into its owner’s graveyard as a state-based effect. See rule 420.

601.9. An Equipment can’t equip an object outside its controller’s range of influence. If an Equipment is attached to an illegal permanent, it becomes unattached from that permanent but remains in play. This is a state-based effect. See rule 420.

601.10. 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.

Example: In a six-player game where each player has range of influence 1, Alex plays Pyroclasm, which reads, “Pyroclasm deals 2 damage to each creature.” Pyroclasm deals 2 damage to each creature controlled by Alex, the player to Alex’s left, and the player to Alex’s right. No other creatures are dealt damage.

601.11. 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.

Example: In a six-player game where each player has range of influence 1, Alex controls Coat of Arms, which reads, “Each creature gets +1/+1 for each other creature in play that shares a creature type with it.” Coat of Arms will boost Alex’s creatures based only on what creatures are controlled by Alex, the player to Alex’s left, and the player to Alex’s right. It won’t take other creatures into account.

Example: In the same game, Rob is sitting to the right of Alex. Coat of Arms will boost Rob’s creatures based only on what creatures are controlled by Rob and Alex. They are the only two players within range of both Rob and the controller of Coat of Arms.

601.12. The “legend rule” (see rule 420.5e) applies to a permanent only if other legendary permanents with the same name are within its controller’s range of influence.

Example: Alex has range of influence 1, and Carissa has range of influence 2. Rob sits between them. If Alex controls a legendary permanent and Carissa puts a legendary permanent with the same name into play, only the one controlled by Carissa will be put into a graveyard.

601.13. The “world rule” (see rule 420.5i) applies to a permanent only if other world permanents are within its controller’s range of influence.

601.14. 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 419, “Replacement and Prevention Effects.”