A man enters a machine called the Animus that lets him relive the memories of his ancestor, a 12th century assassin named Altair.
Before it became its own thing, Assassin's Creed was pitched internally as 'Prince of Persia: Assassin', meant to be a spin-off of Sands of Time. The story drifted so far from the Prince that Ubisoft eventually cut it loose to stand on its own two feet.
For all his rooftop parkour, Altaïr has one glaring blind spot: water. Jump into a river or the sea and he just sinks, there's no swimming animation in this one at all. Later games quietly fixed this, but the original leaves you stranded if you fall in.
Outside a couple of recognisable names, the voice cast for the original game was made up largely of actors with little to no prior acting experience, a pattern that stuck around for a lot of the series' early entries.
One of Altaïr's marks, Conrad of Montferrat, really was murdered in history, just not in 1191, the year the game is set. Ubisoft's researchers spotted the mismatch during development and decided the story worked well enough to run with it anyway.
