A simulation game gives the player control over a system and shows how that system reacts. The subject may be one household, a farm, a football club, a vehicle, a shop, or an entire city. Players learn the rules, choose how to use limited time or resources, and see the results develop across a match, day, season, or longer campaign.
The Sims 4 uses people and homes as its main systems. Players create Sims with appearances, personalities, and aspirations, design houses in Build Mode, and direct relationships, careers, travel, and daily needs. The Gallery adds creations shared by other players, so a household or room can move between separate games.
Sports simulations use a different scale. EA Sports FC turns passing, shooting, defending, team selection, and player development into match and season systems. Madden NFL includes quick games, an individual career, roster building, and Franchise management across drafts, contracts, game plans, and multiple seasons. These modes can model the same sport at the level of one athlete, one match, or an entire organization.
Other simulations may focus on crops, fishing, construction, transport, economics, or survival routines. Some aim for detailed procedures and realistic limits. Others simplify the subject so that progress is easier to read or so the game can combine simulation with adventure, role-playing, or comedy. The shared feature is not visual realism. It is a set of connected rules that responds to the player's choices and can be understood well enough to plan the next action.