Ice Floe — ruling 1

You may target a tapped creature with Ice Floe’s activated ability.

Ice Floe — ruling 2

The targeted creature is not removed from combat. Its attack will continue as normal.

Ice Floe — ruling 3

If the ability resolves, then the creature gains flying later, Ice Floe’s effect will not end. (The ability checks whether the creature has flying only at the time you activate it and the time it resolves.)

Ice Floe — ruling 4

If the affected creature is untapped by some other spell or ability, Ice Floe’s effect will not end. If you keep Ice Floe tapped, and that creature becomes tapped again, Ice Floe will continue to prevent it from being untapped during its controller’s untap step.

Ice Floe — ruling 5

Ice Floe doesn’t track the creature’s controller. If the affected creature changes controllers, Ice Floe will prevent it from being untapped during its new controller’s untap step.

Ice Floe — ruling 6

If Ice Floe untaps or leaves the battlefield, its effect will end. This has no immediate visible affect on the creature. (It doesn’t untap immediately, for example.) The creature will just untap as normal during its controller’s next untap step.

Ice Floe : règles, fonctionnement et interactions (MTG)

Ice Floe 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

You may choose not to untap this land during your untap step. : Tap target creature without flying that's attacking you. It doesn't untap during its controller's untap step for as long as this land remains tapped.

How it works : Ice Floe

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2008· Wizards of the Coast
You may target a tapped creature with Ice Floe’s activated ability.
No other card is named in this ruling.
#2October 1, 2008· Wizards of the Coast
The targeted creature is not removed from combat. Its attack will continue as normal.
No other card is named in this ruling.
#3October 1, 2008· Wizards of the Coast
If the ability resolves, then the creature gains flying later, Ice Floe’s effect will not end. (The ability checks whether the creature has flying only at the time you activate it and the time it resolves.)
No other card is named in this ruling.
#4October 1, 2008· Wizards of the Coast
If the affected creature is untapped by some other spell or ability, Ice Floe’s effect will not end. If you keep Ice Floe tapped, and that creature becomes tapped again, Ice Floe will continue to prevent it from being untapped during its controller’s untap step.
No other card is named in this ruling.
#5October 1, 2008· Wizards of the Coast
Ice Floe doesn’t track the creature’s controller. If the affected creature changes controllers, Ice Floe will prevent it from being untapped during its new controller’s untap step.
No other card is named in this ruling.
#6October 1, 2008· Wizards of the Coast
If Ice Floe untaps or leaves the battlefield, its effect will end. This has no immediate visible affect on the creature. (It doesn’t untap immediately, for example.) The creature will just untap as normal during its controller’s next untap step.
No other card is named in this ruling.