Metal Gear Acid is a turn-based collectable card game. It was the first game in the Metal Gear series for the PSP. A Java ME version for mobile phones was released by Glu Mobile in 2008 titled Metal Gear Acid Mobile. Acid focuses on turn-based tactics, using a trading card-based system to control the main character's movements and actions. Acid in the name stands for "Active Command Intelligence Duel". The cards are not truly collectable, as the game is complete with a single purchase. However, the game does feature deck design and deck optimization elements. The game allows for multiplayer gameplay by wireless ad-hoc connections of two PSPs. Before each round, the player can customize the deck of cards used by the main characters. Most cards are based on elements spanning the entire Metal Gear series, such as weaponry, characters, and even the Metal Gear itself. When the game is started, the player's hand can consist of a maximum of six cards. The maximum number of cards in a deck increases with overall ...