Here's a breakdown:
* The Sims 4: You can have 8 playable Sims in a single household, and you can have multiple households in a single save file. However, you can only control one household at a time.
* The Sims 3: You can have 8 playable Sims in a single household, with a maximum of 16 households per save file.
* The Sims 2: You can have 8 playable Sims in a single household. The maximum number of households per save file varies depending on your computer's memory and available space.
Note: These are the default limits. You can potentially increase the number of playable Sims per household with mods or cheats, but this can affect gameplay performance.