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. The gameplay elements were largely unchanged from Ground Zeroes, meaning that players will have to sneak from several points in the game world, avoiding enemy guards, and remaining undetected. Included in Snake’s repertoire are binoculars, maps, a variety of weapons, explosives, and stealth-based items such as cardboard boxes and decoys. 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. 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, occasionally, players can opt to go rock climbing as a shortcut. They may call for helicopter support against enemy soldiers or request airstrikes that can bomb the target area or change the current weather. Snake can call on AI 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 and trained on the new Mother Base to assist him in the field. The companions’ abilities and their effectiveness will depend on the player’s relationship with them. There is a large emphasis based on tactics in The Phantom Pain.
As in Peace Walker, The Phantom Pain features a base-building system that allows players to develop weapons and items from their home base. Recruitment of enemy soldiers and prisoners has also 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. Unlike in Peace Walker where players can only see Mother Base from the air, they can 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. Money for upgrading Mother Base’s defenses and technology can be collected from objects found all over the map, such as diamonds, shipping containers, and special blueprint boxes, 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.
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”. The enemy AI has improved in terms of situational awareness. If players frequently use particular weapons or tactics to subdue enemy soldiers, this will see the enemy increase in numbers and be outfitted with better equipment; for example, the frequent use of headshots will see enemy soldiers don metal helmets to make targeting the head harder.
The game has a dynamic weather system and day-night cycle that runs in real-time. 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. 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
Kojima spoke about the restrictive nature of previous Metal Gear Solid titles, saying that they “set [the player] on one rail to get from point A to point B, with a certain amount of freedom between”. In stark contrast, The Phantom Pain offers players new ways of traversal and sneaking methods, such as taking a motorcycle, plane or helicopter to the mission area (however, usage of the former two vehicles was later dropped during development). Players are able to traverse the game world or deploy directly to landing zones that allow for different approaches. A video published after the E3 2015 convention showcased this, with the same mission played four times in a number of different ways: with the player opting for stealth, launching a direct assault via helicopter gunship, attempting to assassinate a target with a sniper rifle, and smuggling an explosive device into an enemy base by way of an unsuspecting patrol vehicle crew. The player’s actions affect the wider game world; for example, sabotaging a radar installation will open up new entry points. The playable world in The Phantom Pain is two hundred times larger than that of Ground Zeroes, featuring a variety of climate conditions and environments. This allows the players to freely roam the map while proceeding to either story missions or sidequests, as in other games with nonlinear gameplay. In addition, players who have previously played Ground Zeroes are able to import save data into The Phantom Pain and gain special perks.