BioShock is a first-person shooter with role-playing game customization and stealth elements, and is similar to System Shock 2. The player takes the role of Jack as he is guided through Rapture towards various objectives. The player collects multiple weapons and plasmids as they work their way through enemy forces. The player can switch between one active weapon and one active plasmid at any time, allowing them to find combination attacks that can be effective against certain enemies, such as first shocking a Splicer then striking them down with a wrench. Weapons are limited by ammunition that the player collects; many weapons have secondary ammo types that can be used instead for additional benefits, such as bullets that inflict fire damage. Plasmid use consumes a serum called EVE which can be restored using EVE syringes collected by the player.The player has a health meter that decreases when they take damage. The player can restore their health with medical packs found throughout Rapture. If the player’s health reduces to zero, they will be regenerated at the last Vita-Chamber that they passed with limited amounts of health and EVE. A patch for the game allows players to disable these Vita-Chambers, requiring players to restart a saved game if the character dies.