|Japanese (base text)||
Many "Alien" monsters have effects that state that if a monster with an A-Counter battles an "Alien" monster, the monster with the A-Counter loses 300 ATK and DEF for each A-Counter on it during damage calculation only. However, while the wording of the card texts is often not clear, this ATK/DEF reduction is a Continuous Effect of the monster with that effect. It is not an inherent effect of the A-Counters; this also means that the ATK/DEF reduction is cumulative with more monsters that have this effect on the field.
Lore-wise, A-Counters take the form of "Corruption Cell "A"", which resembles a gelatinous blob of flesh with a tubular "mouth" and a tail. "Interplanetary Invader "A"" is also apparently an A-Counter that has evolved legs and the ability to control minds without the need of another "Alien" monster.
An A-Counter as it appears in Yu-Gi-Oh! 5D's World Championship 2011: Over the Nexus.
An A-Counter as it appears in Yu-Gi-Oh! 5D's Tag Force 6.
An A-Counter as it appears in Yu-Gi-Oh! Duel Arena, after being placed on a card.
An A-Counter as it appears in Yu-Gi-Oh! Duel Generation.
An A-Counter as it appears in Yu-Gi-Oh! Duel Links.
List of cards that use A-Counters
|Japanese name||Card type||Property|
|"A" Cell Breeding Device||「||Spell Card||Continuous Spell Card|
|"A" Cell Incubator||「||Spell Card||Continuous Spell Card|
|"A" Cell Recombination Device||「||Spell Card||Quick-Play Spell Card|
|"A" Cell Scatter Burst||「||Spell Card||Quick-Play Spell Card|
|Brainwashing Beam||Trap Card||Continuous Trap Card|
|Cell Explosion Virus||Trap Card||Normal Trap Card|
|Code A Ancient Ruins||Spell Card||Continuous Spell Card|
|Corruption Cell "A"||Spell Card||Normal Spell Card|
|Detonator Circle "A"||デストラクト・サークル－||Trap Card||Normal Trap Card|
|Interdimensional Warp||Trap Card||Normal Trap Card|
|Mass Hypnosis||Trap Card||Continuous Trap Card|
|Mysterious Triangle||トライアングル・エリア||Spell Card||Quick-Play Spell Card|
|Planet Pollutant Virus||Trap Card||Normal Trap Card|