Origin Games Won't Install
@lottieto Are you running macOS Catalina? If so, that's the issue: both SimCity and Sims 3 are 32-bit apps, and Catalina is 64-bit only. There's no way around this issue, other than to run a 64-bit version of the games. The App store offers a 64-bit version of SimCity, although you'd have to buy it again. There's no indication that the version available through Origin will be updated. For Sims 3, EA has announced a 64-bit compatible version, to be released (hopefully) some time this year.
Other than that, your options are to play on a different computer, to install Windows alongside macOS (via Bootcamp or Parallels), or to install Mojave on an external hard drive. For the last option, you'd need at least temporary access to a Mac running Mojave or earlier, but you could then boot into Mojave when you wanted to play either game. Let me know if you'd like more information about either of these options.
