The gameplay of Fallout 4 features an open world with free roam exploration, various combat options, and numerous sidequests. The S.P.E.C.I.A.L. skill system allows the player to decide the importance of certain skills upon leveling up. New features include a crafting system, settlements that can be built and managed, and the ability to cook food and craft drugs.
Companion selection is also a key aspect of gameplay, with dialogue options that influence conversation routes and the ability to make use of the Pip-Boy app for convenience. The player must manage their HP (health points) and AP (action points), which can be restored through various means such as stimpaks or cooking food. Exposure to radiation directly affects max health, and the player must find ways to mitigate this effect.