Commandos: Behind Enemy Lines is a 1998 real-time tactics video game developed by the Spanish company Pyro Studios and published by Eidos Interactive. The player assumes the role of an allied officer, who has been entrusted to command a group of commandos on twenty missions. A briefing given before a mission begins is divided into two parts - the first, focuses on the background of the mission and where it takes place, and the second, using the mission's map, details the objectives the commandos must complete, any important information they need to know, and what they must use to escape the area. Commandos features six commandos that the player can control, though each mission gives a specific subset of commandos that the player can use to complete objectives, though a mission is failed if any of the commandos are killed in action. Each commando that the player gets to control has a different set of abilities and equipment that they can use to deal with enemies and help them complete their missions - the Green Beret is able to move barrels, climb rough surfaces, use a lure to distract enemies, and can kill soldiers with a knife; the Marine can dive underwater, use a harpoon gun, can kill enemies with a knife, and can pilot ships and boats; the Driver can drive vehicles and operate tanks and mounted guns, and is one of two commandos who can treat the injuries of his comrades; the Sapper is capable of using grenades and handling explosives, can cut through wire fences and set up traps; the Sniper can use a sniper rifle to take out targets, and the second commando who can treat his comrades injuries with a first aid kit; the Spy can wear enemy uniforms, distract soldiers when disguised as an officer, and can kill enemies with a lethal injection. In addition to their abilities, all commandos carry a handgun that they can use as a last resort to defend themselves. The game's emphasis is towards stealth and carefully planned tactics rather than gun battles, as the commandos will not survive for long if shot at. The enemies are divided into ranks - soldiers, who are armed with rifles or MP40 sub-machine guns; sergeants, armed with service pistols, with some manning fixed machine-gun nests; and officers, who are armed with pistols. In addition to foot soldiers, some missions include enemy tanks and armored cars operating in the area. As a rule, all enemies are on alert, and thus man guard posts or conduct patrols in the area, either by themselves or a group of three or four, searching for anything suspicious. The player can monitor the line of sight of the enemy during a mission and use it to plan their moves, although they can only keep tabs on a single enemy's field of vision at any one time. An enemy's field of vision is represented by a cone in front of them, colored green, that extends out from an enemy to a certain distance, and is divided into two sections - close range, represented by light green, in which commandos will be spotted if they step into this area; and long range, represented by dark green, in which commandos will only be spotted if they are standing up when they step into this area. If any commando is spotted, enemies will usually order them to halt in order to capture them, and will only fire on them if they fail to comply or witness any hostile action. If an enemy detects something suspicious, such as seeing footprints or dead bodies, or hearing gunshots and other unusual noises, they will immediately investigate what the cause is. In most missions, an alarm will be raised if the enemy discovers they are under attack, such as an explosion happening in their vicinity. When this happens, the enemy will be more active and will more likely shoot the commandos if they see them, and more soldiers will deploy from garrisons, marked by flags, to patrol the area. If the alarm is raised, the completion of a mission is made much more difficult; in some missions, the sounding of an alarm will cause instant mission failure.