Ubisoft is offering to give a refund to gamers who purchased Assassin's Creed: Unity just before it gave away the game for free as a show of solidarity for Parisians who lost a major part of the Notre Dame cathedral in a recent fire. If you paid full price for the game between April 15 and 17, you don't have to do anything. You should receive an email from Ubisoft shortly with an offer of your money back — and you get to keep the game to boot.
"In light of recent events we wanted to give everyone the chance to experience the majesty and beauty of Notre-Dame the best way we know how and we decided to give Assassin's Creed Unity on PC for free," Ubisoft said on its support site. "If you purchased the game after Monday April 15th at 2:00 PM EST before we made it available for free today, we will reach out to you regarding a refund of the order."
Ubisoft is limited the refund to PC purchasers only, as the original free offer was a PC exclusive one.
Although we would expect the number of gamers to have purchased AC: Unity on those very specific days to be rather small in number, it's a nice touch of Ubisoft to give them their money back so they don't feel like they missed out with their buy.
The reason this all ties into the fire damaged Cathedral in Paris is because Unity is set during the French revolution in the late 18th-century. It's now considered somewhat of a historical artefact itself, since it shows the Cathedral in a relatively modern guise and was modelled exquisitely by the developers to best reflect its beauty and grandeur in the game.