Re: how many devices can i download the sims 4 on?

To my knoweledge you can have the game on 5 computers. You can only play with one at the time, so when you try to run it on two at a time it won't work.

The Origin that is logged in will be logged out when another computer logs in to it. 

On this page: https://myaccount.ea.com/cp-ui/security/index you can see what devices are "trusted" you can get to that page through the Origin menu > EA account and billing.