https://www.pcgamer.com/black-ops-4s-blackout-mode-is-going-free-for-a-week/

Beginning January 17, Call of Duty: Black Ops 4's Blackout battle royale mode is going free for everyone for a week. Neither Treyarch nor Activision have announced a start time at this point, or anything else in the way of specifics, but you will need a Battle.net account if you're curious and don't yet have one.   

"Blackout’s shooting easily outclasses the slightly-clunky gunplay of PUBG," we said in our review, "while the smaller map and the generous distribution of quality loot produce a much faster, more thrilling game that's more akin to Fortnite." But its price tag is a real barrier for the casually curious, so this is a good opportunity for that particular demographic to see what it's all about.