Turri Island — ruling 1

A plane card is treated as if its text box included "When you roll {PW}, put this card on the bottom of its owner's planar deck face down, then move the top card of your planar deck off that planar deck and turn it face up." This is called the "planeswalking ability."

Turri Island — ruling 2

A face-up plane card that's turned face down becomes a new object with no relation to its previous existence. In particular, it loses all counters it may have had.

Turri Island — ruling 3

The controller of a face-up plane card is the player designated as the "planar controller." Normally, the planar controller is whoever the active player is. However, if the current planar controller would leave the game, instead the next player in turn order that wouldn't leave the game becomes the planar controller, then the old planar controller leaves the game. The new planar controller retains that designation until they leave the game or a different player becomes the active player, whichever comes first.

Turri Island — ruling 4

If an ability of a plane refers to "you," it's referring to whoever the plane's controller is at the time, not to the player that started the game with that plane card in their deck. Many abilities of plane cards affect all players, while many others affect only the planar controller, so read each ability carefully.

Turri Island — ruling 5

Turri Island's first ability can't reduce the cost to cast a creature spell to less than {0}.

Turri Island — ruling 6

If there are fewer than three cards in your library as the chaos ability resolves, you'll reveal all the cards in your library.

Turri Island : règles, fonctionnement et interactions (MTG)

Turri Island is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Creature spells cost less to cast. Whenever chaos ensues, reveal the top three cards of your library. Put all creature cards revealed this way into your hand and the rest into your graveyard.

How it works : Turri Island

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2009· Wizards of the Coast
A plane card is treated as if its text box included "When you roll , put this card on the bottom of its owner's planar deck face down, then move the top card of your planar deck off that planar deck and turn it face up." This is called the "planeswalking ability."
No other card is named in this ruling.
#2October 1, 2009· Wizards of the Coast
A face-up plane card that's turned face down becomes a new object with no relation to its previous existence. In particular, it loses all counters it may have had.
No other card is named in this ruling.
#3October 1, 2009· Wizards of the Coast
The controller of a face-up plane card is the player designated as the "planar controller." Normally, the planar controller is whoever the active player is. However, if the current planar controller would leave the game, instead the next player in turn order that wouldn't leave the game becomes the planar controller, then the old planar controller leaves the game. The new planar controller retains that designation until they leave the game or a different player becomes the active player, whichever comes first.
No other card is named in this ruling.
#4October 1, 2009· Wizards of the Coast
If an ability of a plane refers to "you," it's referring to whoever the plane's controller is at the time, not to the player that started the game with that plane card in their deck. Many abilities of plane cards affect all players, while many others affect only the planar controller, so read each ability carefully.
No other card is named in this ruling.
#5October 1, 2009· Wizards of the Coast
Turri Island's first ability can't reduce the cost to cast a creature spell to less than .
No other card is named in this ruling.
#6October 1, 2009· Wizards of the Coast
If there are fewer than three cards in your library as the chaos ability resolves, you'll reveal all the cards in your library.
No other card is named in this ruling.