Just a little under three months from now Infinity Ward’s triple-A monster, Call of Duty: Modern Warfare 2, should be sitting quite comfortably in any avid gamer’s disk drive. Everyone’s been blown away by the trailers, screenshots, awesome graphics and game play videos, but in the wake of all these things, and the awesomeness (it’s a word) contained within them, it’s easy to forget that Call of Duty was not always like this.

It all began back in 2003 with the release of the first Call of Duty. The game took the PC world by storm with its realism and unique take on the single player campaign. You played as American, British and Russian soldiers in three separate campaigns, not just an American as had been done in Medal of Honour up to that point. This was important as it meant you weren’t some big, war winning, bullet proof hero: you were just an average, everyday soldier fighting for your life with your team-mates.

The game also introduced a staple of later Call of Duty’s whereby your AI team-mates and enemies would generally keep re-spawning until you advanced which meant that while you never quite led the charge, you were always an integral part of it. And oh what intelligent AI that game had. Current game series could learn a thing or two here.

The success of Call of Duty prompted the series first foray onto consoles a year later in 2004 in the form of Call of Duty: Finest Hour. It was similar to the first game in gameplay but had a completely different storyline and characters. Finest Hour wasn’t as well received as the PC outing of 2003 due to being, some thought, too action packed. It was a rocky start for COD on consoles, but a start nonetheless.

By Christmas of 2005 the Xbox 360 had found its way into gamer’s homes. There were numerous games in the first next-gen console’s launch line up and foremost among them was Call of Duty 2. This was the first in the series that I played and it remains one of my favourites to this day. It effectively had all the features that the first one did such as brutal AI, excellent characters, well thought out campaigns and a fun and engaging multiplayer suite only this time it was all in glorious HD. I loved the thrill of fighting in the narrow streets and bombed out ruins of Stalingrad where I felt the gameplay mechanics of Call of Duty applied themselves very well.

Similarly the desert combat levels of the British let me see WW2 from a perspective my fifteen year old mind had never visualised before. The American campaign had some stunning set piece levels but they all felt a little generic to me. The exact number of hours I spent in local multiplayer, and then online multiplayer when I subscribed to XBL, have been lost to the dusts of alcohol induced memory lapses and all night gaming binges but they were some of the best times I will ever not remember clearly.

Call of Duty 2: Big Red One marked Treyarch first foray into the franchise in the same year and was the PS2/GC/Xbox version. It differed from previous Call of Duty’s by focusing on a single campaign and was well received by critics but was somewhat overshadowed by it’s next gen counterpart. This marked Treyarch’s first ominous step into Infinity Ward’s considerable shadow.

Call of Duty 3 saw Treyarch at the helm once more and was the first main sequel in series to be console exclusive. Call of Duty 3 felt like far more of a blockbuster experience than previous titles, with some serious character and plot developments taking place in its cut scenes.

You begin to feel a real connection with some of your squad mates by the end of the game and you really feel a loss when a couple of them don’t make it along the way. This time around Treyarch took up its predecessor’s methods and had you play as three different nationalities (American ranger, British SAS paratrooper, Polish tank commander) each with unique styles of mission, all of which become intertwined towards the end.

Again it was a very good game that was well received by critics but it was criticised for not really doing much different from the games before it. WW2 was getting old and Call of Duty was in danger of becoming stale. It was back to infinity ward for the next Call of Duty, and something drastic would have to be done to revitalise the series. Turns out they had a pretty good idea to mix things up a little.

2007: a year of some seriously good games. Halo 3, Mass Effect, Bioshock, The Orange Box and more vied for supremacy but standing head and shoulders above its peers was a little game called Call of Duty 4: Modern Warfare. This game was Call of Duty in name and quality only. It put down the Garand and picked up the silenced MP5, got off the landing craft and clambered aboard the Black Hawk, eschewed open warfare with ze Germans in favour of covert ops and military raids in Russia and the Middle East, then took the world of gaming by storm.

Taking some cinematic cues from Call of Duty 3, Modern Warfare built upon everything the franchise had done up until then with new ideas like perks and class customisation, a blockbuster and deeply personal campaign experience, superb AI and awe inspiring graphics. The multiplayer is still one of the most played on XBL – generally fighting Halo 3 for the top spot – two years on which speaks for its longevity, with collectable items and achievements made the campaign worth playing multiple times also. Overall it’s one of the most rounded games I’ve ever had the pleasure of playing although the multiplayer began to lose its appeal around the second time I reached the highest rank.

Nobody thought that Treyarch could possibly match Infinity Wards most recent outing (including myself) and when World at War was announced, along with its world war two setting, gamers suspicions seemed all but justified. When the game came out however, the world was pleasantly surprised. What we got may not have been anything substantially new, but it did have a very different feel to previous Call of Duties. The two campaigns, one in the Pacific theatre and one in the Soviet march on Berlin, cover areas not really covered by other WW2 game’s which keeps the genre somewhat fresh despite the setting. Also of note was the presence of gore, which had always been left out of previous Call of Duties.

World at War displays a violent brutality befitting of the period, but keeps it disturbing as opposed to over the top. Things like when you blow someone up with a grenade and they lie on the ground clutching their mangled legs, screaming in agony, or when you counter attack a banzai charger by jamming a knife into his throat, setting someone on fire with the flamethrower and watching them writhing and howling in pain until eventually they stop moving. Even the first level opens with a torture scene.

The Pacific campaign sees you on the receiving end of much brutality and forces you to respond in kind, whereas the Soviet campaign generally sees you watching scenes of brutality and questionable morality – such as the execution of a German soldier trying to surrender. While some people consider this controversial and inappropriate for a video game, I say that it is more than appropriate.

Call of Duty has always been a series based around period authenticity, and these are sights and experiences that these soldiers would have gone through. It’s not thrown in there for entertainment. It shouldn’t make you laugh out loud. It should make you question the moral reasoning behind why we have wars and make you feel a degree of respect for the brave soldiers, on both sides, who had to go through this stuff for real.

On a less sombre note, the multiplayer was also pretty good in World at War, largely because it was more or less the same as Modern Warfare, complete with perks, custom classes, challenges and so on. This is both good and bad. Good because Modern Warfare had a really solid multiplayer set up, bad because the only real difference is the guns and the maps. At first I was a bit unsure of the I felt that Treyarch played it a little too safe in this department and, had they been a little more bold, could have produced something even more wonderful.

They did however expand the experience a little with things like co-op and a quirky (and insanely addictive) zombie Nazis mode. Zombie Nazis is probably my personal favourite part of the package. At first I thought it might be morally dodgy, but its light hearted take on the whole affair, with its set of stereotypical character parodies, is actually quite endearing.

Overall World at War was a well received game, criticised only for its lack of any meaningful expansion of the success of Modern Warfare.

And so here we stand, on the cusp of what could well be Game of the Year 2009. Modern Warfare 2 looks set to expand on all the things that made Call of Duty 4 such a success (and although it’s doubtful, I’d love a Nazi Zombies game mode equivalent too). While I don’t think the story will be as good, the experience should be awesome, and the multiplayer will dominate XBL for years to come. Modern Warfare 2 will be released on November 10th. See you then.