Call of Duty: WWII multiplayer action is free for everyone this weekend—in fact, the free weekend is live as we speak. To take part, just pop over to Steam, find the "multiplayer free weekend" link (it's a little hard to see, but you can find it sitting just above the topmost "Buy Call of Duty: WWII" link), and give it a little click.
Then be prepared for a wait, because it's about a 57GB download. But once that's done you can play your face off until 1 pm ET on February 25. Any progression, items, and unlockables earned during the free weekend will carry over if and when you spring for the full game.
It's hard to go wrong at the price, but Call of Duty: WWII's multiplayer is really quite good: We said in our review that the single-player campaign is largely "rote," but the multiplayer "recalls the glory days of Modern Warfare." That's quite a compliment, although doesn't seem to have done much good for the player count: CoD may be more of a console-focused pursuit but even so, today's peak concurrent player count on Steam of just 796 is not great for a game that's been out for less than four months.