The Sims 4 is built upon the same concept as its predecessors. Players control their own Sims' activities and relationships in a manner similar to real life. The gameplay is open-ended and does not have a defined goal. New to this iteration, Sims will be able to do multiple tasks at once, such as talking and strolling at the same time. Traits, actions, and social conduct combine to influence the emotions, personality, and later actions of Sims. Emotional state is reflected in the user interface and in the Sims' expressions. Characters with a higher skill set can mentor peers with lower skills to provide faster skill leveling.
New methods of demise have been included in the game, including death by laughter.
The Create a Sim tool has been redesigned to allow manipulation of Sims' physical features by clicking and dragging the body part. The ability to customize a Sim's voice, walking style, and preset a clothing style has been added. Combinations of traits aggregate to create a hidden trait that is available to only Sims with that set of traits.
Willow Creek and Oasis Springs are included as the default neighborhoods in The Sims 4. Oasis Springs is set in a desert oasis, while Willow Creek showcases gardens and hills as part of its terrain.
Build mode includes the ability to place predesigned rooms and then modify them, add foundations after a home has been built, place all windows simultaneously, and reshape windows. Rooms and houses can be moved as a whole after completion.
Players can import Sims, lots, and rooms from a user-generated database. The downloaded Sims retain their custom personalities and emotions as before they were uploaded. Shared rooms and houses can be also be moved as a whole with all original objects.