Ubisoft has just announced that Tom Clancy's Rainbow Six Siege will be playable for free from February 15 to 20.
As usual, if you purchase the game after this free weekend, your progress will be kept ! You will be able to continue playing without interruption (except for the Starter Edition).
Also note that the content of Season 1 of Year 3, Operation Chimera, will be deployed on test servers (only on PC) from February 19 pending its deployment on all platforms on March 6. The new Outbreak co-op mode (where two new biological attack agents will appear) will be deployed on PC test servers on February 20 and will be available on all platforms from March 6 to April 3 inclusive.
More information on the new Agents and Outbreak mode will be presented at the Six Invitational Finals in Montreal, February 16-18, on Ubisoft's Twitch where you can catch up with Scok.