April 2017 - last edited April 2017
Also, if you own the Sims 3 Starter Pack, It will have a program called Sims3Setup on the disk itself, which bypasses the installation of Origin all together. Just found this out today, since the latest version of Origin only shows a white box instead of any graphics. Don't you just love when they bump the system requirements of the installer/client itself without warning?
EDIT: Origin is still required to launch the game, unfortunately.
April 2017
@-ea-Terminator82 You can still use the discs but you have to use an older version of your operating system. TS3 was released with SecuROM and SafeDisc. Windows 10 and El Capitan no longer support the poorly supported SecuROM and SafeDisc. The Sims 3 1.69 patch can only be obtained through Origin. When Origin patches to version 1.69 SecuROM and SafeDisc are disabled/removed from the game and Origin (Steam like DRM) becomes the DRM. This eliminates the install limit and you no longer require a disc to play. SecuROM was considered a rootkit and usually caused more issues for legal user then kept the game from getting pirated. I use both Steam and Origin and have no issues.
August 2017
April 2018