Wills the Sims 3 Ruin My MacBook Pro?

@Mackenziem26  Modern hardware is very good at throttling performance to help control temperatures.  This can fail if a fan fails, or if a vent is blocked, but generally speaking, hardware will protect itself before it gets damaged.  With Sims 3, there's the additional consideration that it doesn't have a working fps limiter.  Running a game at extremely high framerates can be damaging to a graphics card over the long term, even absent heat issues, so players in Windows generally need to cap fps with an outside tool.

MacOS is actually more aggressive than Windows in these matters.  For example, I played on my 2017 15" MacBook Pro for about five months in macOS, and my framerates were consistently around 80-90, with spikes in certain situations.  Then I Bootcamped my Mac and started playing in Windows, and fps was in the 300s before I manually capped fps to 60.  I don't have a good comparison for temperatures, but I never had any serious heat issues in either OS, and the Mac side never had an fps limiter.

If you want to keep track of how your hardware is performing, you can download iStat and check internal temperatures periodically.  Your 13" MBP doesn't have a dedicated graphics card, so framerates are less of a worry—the integrated Intel chip isn't capable of generating excessively high fps.  So as long as the temperatures are okay, I wouldn't worry.

One thing to avoid though is leaving the game running while idle for an excessive amount of time.  Walking away for a few minutes is fine, but leaving it for an hour might not be a good idea, nor would closing the laptop and coming back later.  I doubt it's immediately damaging, but it's still better to shut down and restart if you're not going to be playing for a while.