That is PC (Epic Game Store, Ubisoft Store - pre-load from tomorrow), PS5 and PS4, as well as Xbox One and Xbox Series X|S. Boy we have a lot of gaming platforms at the minute. At any rate, the very respectable Watch Dogs: Legion is up for free play this coming weekend, March 26 - March 30.

Here's Ubisoft's free pitch:

Every character in near-future London will be available to recruit and play as during the Free Trial Weekend in both single-player and online modes. Players will be able to check out all of the open-world activities such as playing darts at the local pub and participating in bareknuckle fights, as well as explore half of the eight boroughs including the City of London and Islington & Hackney. Additionally, players will be able to discover the game’s storyline up to the Skye Larsen mission.

Additionally, if the game's "recruit and play as anyone" hooks you, Ubisoft has a few sweet post-free weekend buy-in deals:

Players who want to continue their fight will keep their game progression and enjoy discounts on Watch Dogs: Legion and the season pass across select platforms:
• Xbox: From March 25th to April 15th – 50% off of the Standard and Ultimate editions.
• PlayStation: From March 25th to 31st – 50% off of the Standard and Ultimate editions and 25% off of the season pass
• Ubisoft Store on Windows PC: From March 19th to April 9th – 50% off of the Standard, Gold & Ultimate editions, and 25% off of the season pass
• Epic Games Store on Windows PC: March 26th to April 8th – 50% off of the Standard, Gold & Ultimate editions, and 25% off of the season pass

More information on the Free Trial Weekend, including exact timing, can be found here.

Furthermore, Ubisoft has detailed the availability of the free post-launch content for all Watch Dogs: Legion players as well as the new, exclusive content for season pass owners across single-player and online modes.

The post-launch content for all Watch Dogs: Legion players include:

• Today, March 24: Leader of the Pack, the first Tactical Op which will require teamwork and efficiency, is available to play in the online mode of Watch Dogs: Legion. Working with a whistle-blower, DedSec uncovers a deadly initiative that brings the next level of hive-mind based AI on Urban Drone Warfare. They must race to stop the program at its tracks and will discover a hidden terrifying threat at the heart of it all.
  
• In late-May, players will have access to two new PvP modes: Extraction and fan favourite, Invasion, and a new Tactical Op, Project Omni, in the online mode of Watch Dogs: Legion. Project Omni is intense and challenging and will need a team of four to infiltrate a secret project to find out why Londoners’ Optik devices are negatively affecting their brains.

For Season pass owners:

• In late-April, Mina, a subject of transhuman experiments, who possesses the ability to mind control individuals will be available alongside a new mission.
  
• Late-June will see the release Watch Dogs: Legion – Bloodline, a new storyline which includes Aiden Pearce from the original Watch Dogs game and Wrench from Watch Dogs 2 fully playable in the single player campaign and online.
  
• In August, Darcy, a member of the Assassin Order from Assassin’s Creed® will be available as a new playable character alongside new missions.

But enough from us and them, check out a trailer highlighting all of this embedded below.