Many features introduced in the expansion packs, like weather from Seasons and driving cars in Night-life, were going to be in the base game. However, due to an office server room fire in Maxis, the data for these and many others were lost.

There is an unfinished and normally inaccessible aspiration called "Power" in the game. It has some similarities to the "Popularity" and "Fortune" aspirations. Some NPCs and premade deceased sims appear to have this aspiration, and it can also be assigned to a sim using the Sim Modder cheat object.

The track "Arch of the Sims" from the The Sims 2: University expansion pack which plays during build mode, was later used for the Season 4 DVD gag reel of the TV drama Breaking Bad in 2012.

At the start of the game, Brandi Broke is pregnant with her third child and the last conceived with her late husband Skip. However, due to Skip's genetic file being unlinked, the baby will take Brandi's genetics, and will always be male, essentially always making him an opposite sex clone of his mother. Linking Skip so that he is properly linked before the baby is born will result in the baby being born with the genetics of Brandi and Skip, and the chance of it being female.

There is an error with her memories in that she gave birth to their second child Beau after Skip died, yet her third child is recognized by the game as his. Since Brandi could not have gotten pregnant with the third child when she was already pregnant with Beau, Skip could not be the father unless he somehow impregnated her post-mortem. This, however, contradicts a picture in the family album that shows Brandi about to give birth to Beau with both Skip and their first child Dustin present.

During the 7th episode of the EA Community Team Cast, series executive producer and general manager Lyndsay Pearson claimed that the memory contradictions were an oversight, and that the "cloning" technique was used because the data for Brandi's pregnancy kept getting lost.