Metal Gear Solid V: The Phantom Pain is a stealth game in which players take the role of Punished "Venom" Snake from a third-person perspective in an open world.[1] Gameplay elements are largely unchanged from Ground Zeroes, meaning that players must sneak from several points in the game world, avoiding enemy guards, and remaining undetected.[2] Included in Snake's repertoire are binoculars, a variety of weapons, explosives, and stealth-based items such as cardboard boxes and decoys.[2][3] Following one of the series traditions, The Phantom Pain encourages players to progress through the game without killing, using non-lethal weapons such as tranquilizer darts to subdue enemies.[4] Players may traverse the game world with vehicles such as jeeps and tanks, in addition to traveling on foot or on horseback, and as certain locations are mountainous,[5] occasionally, players can opt to go rock climbing as a shortcut.[6] They may call for helicopter support against enemy soldiers or request airstrikes that can bomb the target area or change the weather.[7] Snake can call on AI "buddy" companions—including Quiet, a silent female sniper with supernatural abilities; D-Horse, a horse capable of wearing armor and hiding Snake during travel; D-Walker, a manned, highly agile mobile weapons platform that can provide heavy weapons support; and D-Dog, a wolf pup raised to assist him in the field.[3][8][9] The companions' abilities and their effectiveness depends on the player's relationship with them.[7] There is a large emphasis on tactics in The Phantom Pain.[10]As in Peace Walker, The Phantom Pain features a base-building system that allows players to develop weapons and items from their headquarters, Mother Base.[11] Recruitment of enemy soldiers and prisoners has returned for this purpose, allowing the base to grow through organization. The player is given the option to access their base from their real-life smartphones and other devices via a companion app.[12] Unlike in Peace Walker where players can only see Mother Base from the air, The Phantom Pain allows players to control Snake as he explores the complex on foot. The Fulton surface-to-air recovery system, an item introduced into gameplay in Peace Walker, returns as well, with players able to transport captured soldiers and other objects such as animals and vehicles back to Mother Base.[13] An in-game currency called GMP is used for upgrading Mother Base's defenses and technology, and can be collected from objects found all over the map, such as rough diamonds, shipping containers, and special blueprint boxes,[9] as well as sending recruited soldiers on combat missions around the world. The income is invested in upgrades to the appearance and abilities, weapons and equipment of Snake, his AI companions, and vehicles. For example, Snake's prosthetic arm can be modified with a taser, echolocation function, or remote controls that allow it to fly as a drone.[14][15]Game design direction allows the player to choose in what order the story events take place by selecting missions in any order they like, and yet still "understand the encompassing message by the end".[16][17] The enemy AI has improved in terms of situational awareness. If players frequently use particular weapons or tactics to subdue enemy soldiers, enemies will increase in number and be outfitted with better equipment; for example, frequent use of headshots will result in enemy soldiers donning metal helmets to make targeting the head harder.[18] Other actions from the player can affect the wider game world further; for example, sabotaging a radar installation will open up new entry points.[19]The game has a dynamic weather system and day-night cycle that runs in real-time.[20] The cycle is able to be fast-forwarded when Snake lights a "Phantom Cigar", a type of electronic cigar; a digital silver Seiko watch panel appears on screen to denote time.[21] The passage of time enables players to analyze the movement of marked enemy forces in the area, such as shifts in sentry patrols and individual patrol routes. Weather effects, such as sandstorms and rain, affects the gameplay environment by reducing visibility or masking the sound of footsteps.[22]