The influences here are manifold and not all are obvious. But Ubisoft's latest killer, who we can reveal is coming to PC, is more than the sum of his parts.
Similarities to Prince of Persia should come as no surprise - it's the same core team of developers. And nor, you might think, would a stealth element be a shock with Splinter Cell emanating from the same company. However, you'd be a little way off track there. On the other hand, Hitman, Robin Hood, Raiders of the Lost Ark, Madden, the Crusades, horses and free running are more relevant than they'd seem.
Assassin's Creed involves stealth, but it takes place almost totally during the day. Your cover is normality itself: evasion and success come from blending in with the crowds. There's no squatting in shadows or waiting behind boxes; Ubisoft's aim here is to make things work according to the existing social rules of the real world, rather than the contrived ones of videogaming.
This way, the thinking goes, the game will be both more accessible to non-gamers (because everybody already inherently understands it) and more immersive at the same time, because cause and effect are familiar, testing the player's suspension of disbelief less. Fine. So how does it work?
As the white-clad assassin Altair, you visit the 'bureau' in order to pick up jobs, but its 1192 and sadly there's no radar. You have no idea where your target is, so your first task is to gather intel through eavesdropping and the like. Once you have an idea, how you travel through the three large cities - Acre, Damascus and eventually Jerusalem - is up to you. It's possible to take the streets and back alleys, using crowds as cover, so long as you're discreet. Go slow, be polite and slip through the gaps and progress will be simple. Barge through, shoving people away and resentment towards you will soon build to critical levels.
Crucially, individuals who dislike you will obstruct you or alert various enemy forces such as Crusaders; those on your side may obstruct your pursuers or even misdirect them. The crowds here (boasting individual AI and "several hundred" character models) have even more of a presence and importance than the impressive Hitman; Ubisoft want to evoke the physicality of blocking and balance issues already present in sports games such as Madden.
An alternative is to head up onto the rooftops to stalk your prey. There are no dedicated routes - anything you could humanly reach that has at least a 10cm toehold can be scaled. Hence the freerunning... and it's all about the elegance. Jumping is automatic, but once in the air your arc cannot be changed - again, the reasoning comes from reality. It's easy to perform a jump in real life; the trick is judging it so you land in the right place.
The authenticity is not totally slavish. From on high, Altair can better use his Eagle Eye ability, which colour-codes friendlies, enemies and targets for a tactical overview - but realism does extend to the kill. One good hit from a sword or crossbow is deadly, and that goes for everyone. To keep this fun, Altair has an automatic blocking ability... as does everyone else. The trick to combat, then, is in the timing, slipping the fatal strike through a man's defences before he does it unto you. Then for the final part: escape.
You've just whacked some corrupt religious psycho in broad daylight. We've all done it. But everyone's gone a bit funny. Guards are running and civilians are panicking. If you've been working the people-helping side-missions, saving harassed innocents from God-botherers or pickpocketing rich types to give to the poor (hence the Robin Hood angle), the public can help shield you (see left). Or you can escape over the roofs, or sit on a bench and pretend to be talking to someone. Or drop your head and mingle with praying monks.