The Sims 4 is the fourth main game in the real-time life simulation / management series. Just like the previous games one or more custom characters are created through Create-a-Sim to live in a house designed by the player. As their lives unfold based on the environment, relationships and specific traits, the player gets to manage the life, needs to organize activities, attend to needs, and react to moods, with non-linear gameplay and no direct control.

The character creation process has been expanded. Players choose a gender, age (from child to elder), look and outfit. The voice can be adjusted from clear to brash and a specific walking style can be chosen to reflect the personality. Next to a selection of various facial and body features, every element of the character can also be tweaked by holding and dragging with a large choice of colours and accessories. Players also choose a lifetime aspiration from a number of fields such as athleticism, creativity, family, knowledge, love ... with deeper choices for each. Next, three traits (one less than the previous game) are selected such as active, cheerful, gloomy, romantic or self-assured, and specific characteristics such as hobbies, lifestyle and social intelligence. The game puts a larger emphasis on personalities and social interactions. Sims are now for instance also able to multitask, rather than completing actions one by one, and these are also affected by moodlets and emotions. While playing players are rewarded for reacting to moods, providing temporary buffs or permanent enhancements to the Sims, for small accomplishments. The available interactions are largely based on the chosen personality.

The bottom left of the interface holds an action queue where various activities the Sim wants to do are listed. At the bottom are time controls to manage how time passes. There is free camera rotation and various zoom levels to follow the activity from any angle. Sims level up by practicing activities. The game's main currency Simoleons is used to provide for the chosen lifestyle and to buy new items. The build mode has been made easier as items now often click together to form a coherent structure. Entire rooms can be picked up and placed elsewhere and the push-and-pull tool from the character creation mode can be used to alter the walls. The game has two neighbourhoods with ten public venues in total, such as bars, a museum, a park, a gym, and a library. Work locations and co-workers are not shown in the game.

The Create-a-Style mode from the previous game where surfaces and textiles could be painted with a custom design has been dropped in favour of predetermined colour sets. The game also no longer employs a seamless open world for different locations, but links together smaller environments with loading screens. All of the terrain has been flattened, without hills, and transportation is no longer present.