You're not ready for Doom. You're really not. This morning I played an hour of back-to-back games in the new demon-bothering shooter's versus multiplayer, and my head still isn't right. It is, however, very happy.

Doom, you see, is intense. It's intense in ways we haven't seen in a mainstream FPS for quite a while. It's not just the aggression, or the speed, or the gibs (though all of those things certainly factor in). It's more than that. It's Doom's cleverness. It's Doom's deceptive, layered complexity. It's the constant, gleefully ferocious back-and-forth between demand and reward. Doom is great. And it's messed me up rather brilliantly. Here's why my head is such a giddy shambles right now.

You'll notice this immediately. Doom is fast. And it's not just about Doomguy's immediate running pace, which is both blistering and relentless (no sprint toggle here: you're either charging forth or you're standing still, in which case you're probably dead). It's about the kind of speed that permeates the whole game.

This isn't Call of Duty fast, where running hard and aiming quick are the be-all and end-all. This is multi-dimensional fast. Speed dictates everything. Your forward momentum, your lateral movement (ducking and weaving is a way of life in Doom, due to the proliferation of dodgeable, physical projectiles and lengthy health bars), your vertical movement, your spur-of-the-moment escapes and rapid, rethought retaliations... Your first few games will be spent recalibrating your brain to operate at a rate of knots in every respect. When you get it though, it could not be more exhilarating.

If you have a storied history in multiplayer shooters, there's another aspect of Doom that's likely to throw you off at first. You see, Doom's persona is a little ambiguous. Yes, the tight, intricate map design - packed as it is with opportunities for creative navigation and clever vertical assaults - is pure Doom. But in other respects? There's a whole lot of Quake here.

There's the quad-damage pick-up. There's the springy, double-jumping focus on bunny hops. There's the splattery crowd-control of the plasma rifle. There's the way any of each match's million and one frantic, cat-and-mouse skirmishes can break into explosive, high-flying madness at the drop of a rocket. Reconciling the two games' traditional elements can take a little while. At times it feels like an airier Doom, at other times a tighter, more restrained Quake. Ultimately though, the two games' conceits do compliment each other, leading to a relentlessly aggressive, but pleasingly focused game. And speaking of focus...

Doom might be all about the carnage, but igniting that destruction effectively requires sharp, thoughtful shooting. With a bit of experience using Doom's weapon-set, it quickly becomes apparent that this is not a game that rewards mindless spamming. Its guns are imposing, but to get the most out of them, you're going to have to fight smart and stay on your toes.

The rocket launcher, for instance, is not the easy harbinger of devastation you might expect. Its splash damage area is deceptively small, demanding fast, precision shots and a whole lot of target-leading. The faster-firing weapons can be painfully weak unless you utilize their more powerful secondary modes (such as the repeater rifle's high impact Magnum rounds), at which point even more methodical precision - and sometimes the reduced view of a scope - comes back into play. Doom's equivalent of a railgun is a classic example: a decent, medium-to-long range weapon as standard, which requires a zoomed charge in order to bring the delicious one-shot action. And at no point will Doom slow down enough to make any of this easy. As such...

If you're fighting at medium to long-range and trying to get by with reaction shots, you're already too late. Fact. With no radar, and an arsenal that favors real, physical, trackable ordnance over point-and-click hitscan firing, Doom's combat is all about thoughtful, preemptive play.

You need to predict your opponents' behavior. You need to influence it into advantageous shapes with smart use of weapon switching and spatial control. You're required to understand the many subtle interplays between your weapons' rate (and type) of damage and speed to target, your opponents' probable responses, and your own follow-up options at any given time. In short, if you're not playing with your head two seconds into the future at any given time, you're playing too slowly. And goddamn if that isn't constantly exciting.

Don't go thinking that the intensity of those skirmishes means you're just looking at a few tense flare-ups with plenty of time to recover in between. Doom is relentless. You're never more than ten seconds away from the next scuffle, and even if you manage to stay out of the action for a while, it won't do you any good unless you use that time wisely and bravely.

With no inherent life regen, health and armor pick-ups are your only hope of staying in the fight. They're plentiful, but they're not going to just drop in your lap - you need to seek them out. You're going to have to scavenge. That means build healing break-aways into the entire rhythm and flow of your fighting, often while under fire. And you're never going to know whether a lone-wolf loot run is going to end in your salvation or the exact opposite. When it's the former though, especially with an enemy on your tail, there's no sweeter comeback. As for lone-wolfing it, well...

Yes, Doom looks - and often feels - anarchic, but talking, planning and synergizing with your team is how you're going to stay alive. Given the drawn-out nature of Doom's one-on-one firefights, the numbers game is a big deal. Ideally, you always want at least one buddy on hand to cover angles and call out situations you might not be aware of.

Of course, a fast, creative player can definitely beat stacked odds alone (or at least escape to fight another day), but such situations are certainly best avoided. Especially when the Revenant comes into play...

Every couple of minutes (at least in the single mode shown at Quakecon), a pentagram powerup will drop into the map. Once someone grabs it (following an inevitably intense fight for control of the area), they'll transform into one of Doom's skeletal, rocket-slinging Revenants. They'll do ridiculously overpowered damage. They'll inflict a nasty amount of splash damage. They'll be able to fly. In short, they become a miniboss on the map, fighting on behalf of one team until it either times out or is killed.

The latter is obviously the preferable option, and that's where the real joy of Doom's design comes together. For a team to take down a Revenant quickly, everything previously mentioned has to come together as part of one big, glorious, smoothly cooperative machine. Tight, preemptive play. Smart aggression balanced with canny self-preservation. Insightful understanding of the limitations of attack and defence. A team you can rely on. It's tough. It's grueling. At times it's terrifying. But it's never anything less that triumphant, hilarious, explosive fun. And that, right there, is Doom all over.