According to an FAQ on the Ubisoft Assassin’s Creed website, New Game Plus is available in-game as of today, February 20. You’ll be able to access NG+ in your game after completing the main game for the first time. Specifically, “players can access it by going to the title screen. A new option will be available on your saved game to start an NG+. Once chosen, a new separate save will be created.”
Equipment (weapons, shields, tools, outfits, mounts), abilities acquired and available ability points, crafting status, player level, XP, and inventory (crafting materials, arrows, tools, animal goods, trinkets) will all carry over into NG+. In addition, the game’s difficulty will increase by one level with each new game plus; for instance, normal becomes hard, hard becomes nightmare, and nightmare…remains a nightmare.
Ubisoft also confirmed that there will be a “unique reward” for players who complete the game in NG+, although that reward is going to be a surprise.
NG+ launches concurrently with the Origins Discovery Tour mode, which Ubisoft announced last September. Assassin’s Creed Origins is available now for PC, Xbox One, and PlayStation 4.