Like its predecessor, The Sims 2 allows the player to create and dress characters called "Sims", design neighborhoods, and build and furnish houses. Players manage their Sims from birth to death, forming relationships in a manner similar to real life. Sims have life goals, wants, and fears, the fulfillment of which can produce good or bad outcomes. First incorporated in the console versions of The Sims, The Sims 2 was the first PC game in the series to incorporate a complete 3D graphics engine of the game world. This allows the player to get 360º views as opposed to the fixed 2D isometric view of The Sims. Genetics are also a new game mechanic; children in The Sims that were born in-game were randomly generated. Although gameplay is not linear, storylines and scripted events exist in the game's pre-built neighborhoods.
The Sims 2 was critically acclaimed, and it has been cited as one of the greatest video games ever made. It was also a commercial success, selling one million copies in its first ten days, a record at the time. It contributed to The Sims series reaching 100 million copies in April 2008. By March 2012, the game had sold 13 million copies over all platforms with over six million PC copies, making it one of the best-selling PC games of all time. The game was re-released on Steam and EA desktop in January 2025 to coincide with the 25th anniversary of The Sims series.