https://www.pcgamer.com/the-overwatch-free-weekend-begins-today/

On the off-chance you missed the announcement last week, this is a gentle reminder that Overwatch is free to play this weekend. And even though it's only Thursday, that weekend begins at 11 am PT/2 pm ET today. 

The free-play period includes the full Overwatch roster, including Wrecking Ball, the delightful, mech-driving hamster who rolled off the PTR and into the full fight earlier this week. You'll have access to Quick Play, Custom Games, and the Arcade, and will level up, earn loot boxes, and unlock stuff the same as you would if you owned the game. And if you do opt to own the game when it's all over, any progress you earn during the free weekend will carry over.