If you still haven't played Fallout 4, now you'll have a chance to do it free of charge.
The Fallout 4 free period will run from 5/25/2017 at 10 AM PT through 5/28 at 1PM PT. What this means is you'll be able to play the game's base content free, as well as try out as many Mods as you like.
In addition, Bethesda will be offering savings for Fallout 4's base game and Season Pass from 5/25/2017 to 5/29/2017 at 10 AM PT. You can expect to get up to 67% off if you decide to purchase the latest addition to the Fallout series.