Aliens is a deck that uses A-Counters: These counters are used to activate card effects from monsters, traps and spells. Some Aliens are able to use A-counters to reduce enemy monsters attack and defense, and will have the text “If a monster with an A-Counter battles an Alien monster, it loses 300 ATK and DEF for each A-Counter during damage calculation only.” Alien decks are extremely versitile and have room for situational tech cards, making them a strong deck for experienced players as well.
Aliens A-counter -300 effect stacks, so: 2 aliens (with the text effect) = -600 with 1 counter.
Play “A” Cell Recombination Device on the end phase of your opponent’s turn, this way you can get the effect of adding an alien monster to your hand on your following turn.
Alien Kids effect to place an A-counter cannot be negated by Divine Wrath.
Econ taking an enemys Alien Overlord will destroy theirs and keep yours in tact if you have one on the field.