Elder Scrolls series: thou hast been a "huge" inspiration to gory tropical open world shooter Far Cry 3.

"We've had to take a little bit of a different approach to most shooters," Far Cry 3 lead designer Jamie Keen said at the Eurogamer Expo today.

"In order to keep a player engaged over a period of time there are certain other genres we have to look into to keep that engagement over a longer time. So we've been looking at things like MMOs, we've been looking at other open world titles. The Elder Scrolls series is a huge inspiration for us; games like Red Dead [Redemption] and other Rockstar games as well."

Those games keep you ploughing through the world, all the time rewarding you with the feeling of progression.

"This is a really vast land mass," Keen went on, "and a lot of shooters don't normally have that. So to keep that progression going, to keep those different spacings of where we place stuff in the world, it's important that we're breaking the boundaries of what an FPS normally is."

Everything Keen talked about today concerned creating and populating an open sandbox world, making it feel real. But as much as he's inspired by Skyrim, things like memes emerging from repetitive NPC dialogue is something he wants Far Cry 3 to avoid.

"It's important too that you feel like the world isn't - we don't want you to feel like 'oh it's this encounter again, I've seen this one'. You know, 'arrow to the knee', for example. While the 'arrow to the knee' thing is actually quite cool, we don't necessarily want that."

Far Cry 3 spawns more than 250 different encounter types, Keen revealed, and the game remembers which ones you've experienced recently so as not to throw them at you again.

"You end up with this real feeling of diversity of things going on," he pledged. "And you will see the same encounter again, but hopefully there's enough of them that you won't remember it, probably."

Keen described the Far Cry 3 map as "the most complicated jigsaw puzzle you've ever seen in your life", referring to the difficulties he had matching up locations and quest pacing and all that sort of thing. And that map he wants you to explore "as if you have ADHD": be compelled to explore every nook and cranny.