Alternate universe

The Sims 4 exists in an "alternate universe," separate from the timeline established in The Sims, The Sims 2, and The Sims 3. The alternate universe was created to allow the developers of The Sims 4 more creative control over the Sims and families that appear in the game. It allows well-known and established Sims and families from previous games to appear without disrupting the continuity set by the first three games. Thus, events and Sims which exist in the "backstory" of The Sims 4 can, but do not necessarily, exist within the continuity of the first three games, and vice versa.

Examples of differences between continuities

 * In The Sims 2, it is established that Nighat Caliente is the deceased mother of twins Dina and Nina Caliente. The Sims 4 establishes that Katrina Caliente is the mother of the twins. Additionally, unlike Nighat, Katrina is alive at the start of the game.

Bella Goth appears in the Sims 4 while Mortimer is an adult.

Cassandra Goth is a teenager instead an adult on the Sims 2.