Infinite loop

An Infinite Loop is a never-ending cycle of cards trying to resolve. The following is perhaps the best known example:

Player A has Spell Canceller face-up on the field. Player B has Jinzo face-up on the field.

Player B activates Amplifier. The card effect text states 'This card's activation and effect cannot be negated by any other card.' Player A's Spell Canceller tries to Negate it, but Fails, and the effects must resolve again, because Step 2, Spell Canceller, could not resolve. The loop continues forever ad infinitum.

Another example:

Player A has Ultimate Tyranno face-up on the field. Player B has 2 Ambulance Rescueroids face-up on the feild.Player A enters Battle Phase and Ultimate Tyranno must attack them.But if he attacks 1 Ambulamce Rescueroid, it will return to the field via the other one.Then, Tyranno must attack it again and again, creating the loop

Thus, a ruling was intruduced, that states you may not activate a card knowing that it will cause an Infinite Loop.