Infinite loop

An Infinite Loop is a never-ending cycle of cards trying to resolve.

Because of this, a ruling was introduced that states you may not activate a card knowing that it will cause an Infinite Loop with No Net Change.

• EXAMPLE #1: I have "Pole Position", "Luminous Spark" (+500 to LIGHT), and "Gemini Elf" (1900 ATK / EARTH) face-up on the field. "Gemini Elf" is the monster on the field with the highest ATK, so it is unaffected by Spell Cards. If the opponent Summons "X-Head Cannon" (1800 ATK / LIGHT), "Luminous Spark" will raise the ATK of "X-Head Cannon" to 2300, making it the highest ATK monster on the field, so it's unaffected by Spell Cards, so it drops to 1800 ATK, then increases to 2300, then drops to 1800, etc. This would create an infinite loop. Therefore, the opponent cannot Summon "X-Head Cannon". (Taken directly from "Pole Position's" ruling page)
  • See Pole Position's rulings for other examples of Infinite Loops with No Net Change.

Net Change is when a Loop is activated that has a change occur for certain. After the Loop is active it will continue until it stops producing a change and then the card causing it will be destroyed by Game Mechanics.

• An example with Net Change: The cards "Morphing Jar #2", "All-Out Attacks", and "Hiro's Shadow Scout" are face-down on your field. Activating "All-Out Attacks will flip both your monsters face-up causing both effects to activate and recycle. See the All-Out Attacks OTK page for full details. Some other ideas are listed. When the loop is unable to continue, the faulting card is destroyed by Game Mechanics. In this example, the destroyed card would be "All-Out Attacks".

When the Loop is controlled by a player, the Loop can be stopped at any time by that player. As such, a Controlled Loop is legal for use.

• An example of a "Controlled Loop": The Quillbolt Loop. This uses "Quillbolt Hedgehog's" ability to Special Summon itself by having a Tuner on the field and follows by having a "tribute for damage" card on the field. Using "Imperial Iron Wall" prevents "Quillbolt Hedgehog" from being removed from play. Rinse and Repeat.
• Another example: The Flint Equip Loop. This uses "Flint" and two "Flint Locks" to pass the "Flint" back and forth. The Spell Card "Morale Boost" is used to gain 1000 Life Points every time an Equip Card is equipped. Because no Equip card leaves the field, the 1000 Life Point loss is never reached. This allows a player to gain infinite Life Points while the opponent may be powerless to stop it. Combined with "Fire Princess", this creates an OTK.
• One more example: The Butterfly Dagger - Elma Loop. The player user a Face-up "Royal Magical Library", "Gearfried the Iron Knight" and "Butterfly Dagger - Elma" to draw cards from the deck. Each time "Butterfly Dagger - Elma" is equiped to "Gearfried the Iron Knight" it is destroyed by "Gearfried the Iron Knight's" effect and sent to the graveyard. Since a spell Card was activated "Royal Magical Library" gains a spell counter. "Butterfly Dagger - Elma" is returned to the hand and the loop is repeated. When "Royal Magical Library" has three spell counters you draw a card. Repeat.