Illegal

If a card is illegal, it means it cannot ever be used in tournament play or other official Duels. Illegal cards may only be used in casual play at the agreement of all participants. In general, official cards which are illegal can be distinguished by the presence of Limitation Text (most commonly "This card cannot be used in a Duel.") where the passcode would be normally placed, in the card's lower left-hand corner. All unofficial and counterfeit cards are also illegal.

OCG

	Japanese name	Limitation text	Card type	Attribute	Type	Level	ATK	DEF
"Cyber Dragon" Fusion program			Strategy Card
"Elemental Hero Sparkman's" arsenal			Strategy Card
"Flame Wingman" devastating combo 1			Strategy Card
"Flame Wingman" devastating combo 2			Strategy Card
"Neo-Spacian Aqua Dolphin" Summoning combo			Strategy Card
4-card draw combo			Strategy Card
Aggiba, the Malevolent Sh'nn S'yo	羅（ら）阿（あ）邪（じゃ）神（しん）将（しょう）アギバ	This card cannot be used in a Duel.	Monster Card	LIGHT	Fiend	10	3,000	3,000
Amatsu-Okami of the Divine Peaks	神峰之天津靇（シンポウノアマツオカミ）	This card cannot be used in a Duel.	Monster Card	LIGHT	Dragon		3,000
Attack from the Skyscrapers			Strategy Card
Big Bang Breaker!			Strategy Card
Black Feather fury			Strategy Card
Blackwing flashback!			Strategy Card
Bring "Assault Mode Activate" to your hand!			Strategy Card
Call your Heroes from your Deck!			Strategy Card
Card of Last Will	遺（ゆい）言（ごん）の札（ふだ）	This card cannot be used in a Duel.	Trap Card
Charge into a Synchro Summon			Strategy Card
Chimaera, the Master of Beasts	獣（じゅう）王（おう）キマイラ	This card cannot be used in a Duel.	Monster Card	LIGHT	Beast	9	3,000	3,000
Clear a path!			Strategy Card
Combo Chain!			Strategy Card
Command Duel-Use Card	コマンドデュエル用（よう）カード	This card cannot be in a Deck.	Command Card
Control your own Golem fighting force			Strategy Card
Create a Mammoth defense			Strategy Card
Creator of Hope	希（き）望（ぼう）の創（そう）造（ぞう）者（しゃ）	This card cannot be used in a Duel.	Monster Card	LIGHT	Warrior	2	500	900
Creator of Miracles	奇（き）跡（せき）の創（そう）造（ぞう）者（しゃ）	This card cannot be used in a Duel.	Monster Card	LIGHT	Warrior	4	1,800	900
Crush the competition			Strategy Card
Crystal Tree miracle grow			Strategy Card
De-Fuse and re-use			Strategy Card
Defend your Skyblasters!			Strategy Card
Deploy monsters from the Deck!			Strategy Card
Destiny Hero revival			Strategy Card
Double duty			Strategy Card
Draw like a pro			Strategy Card
Draw more "Elemental Heroes" 1			Strategy Card
Draw more "Elemental Heroes" 2			Strategy Card
Duel Checker	－ＤＵＥＬ（デュエル） ＣＨＥＣＫＥＲ（チェッカー）－	This card cannot be in a Deck.	Non-game card
Duelist ID Card	ＤＵＥＬＩＳＴ ＩＤ ＣＡＲＤ（遊戯王 オフィシャルカードゲーム デュエルモンスターズ）	http://www.yugioh-card.com	Non-game card
Duelist Kingdom (card)	王（おう）国（こく）	This card cannot be used in a Duel.	Ticket Card
Duelist Name Card	ＤＵＥＬＩＳＴ ＮＡＭＥ ＣＡＲＤ（遊戯王 オフィシャルカードゲーム デュエルモンスターズ）	http://www.yugioh-card.com	Non-game card
Duelist Pack - Aster Phoenix - Checklist			Card Checklist
Duelist Pack -JADEN YUKI 2- Checklist			Card Checklist
Duelist Pack -JADEN YUKI 3- Checklist			Card Checklist
Duelist Pack -Jesse Anderson- Checklist			Card Checklist
Duelist Pack -Yusei 2- checklist			Card Checklist
Duelist Pack -Yusei 3- Checklist			Card Checklist
Duelist Pack -Yusei- Checklist			Card Checklist
Duelist Pack -Zane Truesdale- Checklist			Card Checklist
Duelist Pack: Crow checklist			Card Checklist
Duelist pack - CHAZZ PRINCETON - checklist			Card Checklist
Duelist pack - JADEN YUKI - checklist			Card Checklist
Elemental Hero defense			Strategy Card
... further results

Anime

It is mentioned that "Golden Castle of Stromberg", "Infernalvania" and "Binding Swords of Impact" are illegal cards not intended for use.

In Yu-Gi-Oh! ARC-V it is shown that if an illegal card is used, the duel will automatically end.