The bleed effect is just ridiculous. Awesome in its spectacle, brilliant in its execution. It works like this: Diablo III’s monk class plays as if he’s stepped out of God of War, or any other console brawler. If he chains three punches in quick succession, he can set up a finishing move. One is a flashy flurry of strikes like something from the Pokemon cartoons – zipping through the air and hitting everything in range. You could finish your flurry with one epically violent slap – knocking your target backwards with full force through the scenery.

As one demon dies, another rushes in to take his place – it’s Whack-a-Mole played with two mouse buttons and a warrior of unholy fury. Every creature gets a slap, a tickle and a stomp. Unless you want to be really, really clever, which is where the bleed effect comes in. Use this attack, and as a creature bleeds, it takes damage, its health bar ticking away to nothing. And if they die with the bleed still effective, they explode. The destruction is vicious, hilarious – a tsunami of gore. If you set two, maybe three bleeds running, you can time a chain reaction. Bubble Bobble, played with bile and bones. Diablo III is already gloriously, stupidly violent. It’s already brilliant. But it won’t be out until at least 2011.

Leading the Diablo team is Jay Wilson. He’s scruffy in that game developer way: smarts hidden behind a ruff of messy greying hair. Jay has serious form. He came to Blizzard via Relic, after leading the development of Company of Heroes and the Dawn of War games. There, with his designers, he made a point of emphasising violence and destruction. Few who’ve played CoH will forget the crumpled torsos that remain after a well placed artillery shell hits infantry, or the gruesome animation of an ork shredded to pulp in the claw of a Dreadnought.

Jay and his team at Blizzard are applying a similar sense of physical ‘pop’ to the four Diablo III classes revealed so far. The Barbarian is beefcake central. He charges into battle and slaps the monstrous hordes about with hammer blows and straight punches. His special moves, like the cleave (it hits all monsters directly in front of him) are pure melee might, tearing foes in half, or sending their torsos and limbs skittering across the desert sands. The Wizard’s magic missiles have a similar effect – when they strike a skeleton it doesn’t just crumble in a preset animation. Instead, bones scatter as if hit by a truck. Only the Witch Doctor feels like a nimbler, weaker foil, but that’s because he isn’t the one doing the damage. He summons zombie dogs to do the damage for him. And zombie spiders that spawn from zombie corpses. And the now infamous wall of zombies.

Is it Jay’s thing, then, to obsess over the effects of violence? “Yes,” he replies. “It’s something very close to my heart. When something happens, I want to feel it, I want to see it, and I want it to be awesome. And if it’s not awesome, we’re going to keep on working on it until it is awesome.”

As he talks, he becomes more animated – the excitement rising. “That’s something I think Diablo and Diablo II did so well. If you play Diablo II again, do me a favour and go and start a sorceress. Go ahead and hit a Fallen on the head with a staff. It’s the greatest sound in the world! It’s a thonk, right in the side of his head. It’s so good. We focus on that constantly. If it’s not right, I give people no end of grief.”

Diablo and Diablo II are rightly regarded as classics: two infinitely replayable dungeon crawlers that spawned their own genre. They’re also regarded as PC-only classics, but that’s an idea Jay challenges. Not because there are plans for Diablo III to appear on consoles, but to ensure that the console influence is acknowledged. For all its mouse-and-keyboard interface, Diablo plays like a beat-’em-up.

“On the action side, we’re closer to God of War than World of Warcraft. When we were designing the Monk, we pulled a lot of his moves from fighting games and brawlers, even if our overall combat model has more in common with an MMO or a classic RPG. The Diablo games have in their core somewhat arcade ideas. And we’re not afraid to play off that. Like our hit counter system. If you kill 20 enemies in one set of moves, you’ll get a bonus to your experience.”