Preconception is probably the greatest enemy a game designer has to defeat. When a game series becomes a 'franchise' and has reached its third or fourth iteration, people's expectations and preconceptions are always going to edge towards the principle of diminishing returns. So when Empire Total War was announced, I was gripped by the ambivalence of both hope and cynicism. Hope that somehow Empire could live up to the hype, yet cynicism that Total War was now beyond its peak and descending into the grassy paddock to join other cash cow franchises. As we all know, when it comes to psychology mathematics, cynicism trumps hope every time. So my expectations for Empire, along with its much-vaunted naval combat, were not actually that great. Initial impressions were likewise "so far, so familiar", but I was reassured that once I had actually got stuck into a campaign, Empire is not content to rest on the laurels of its illustrious predecessors and is instead intent on treading new ground for the series.

The basic structure of the game remains as before, with the metronomic, gently-paced heart of the game on the strategic campaign map being pierced by the sharp stabs of frantic (and often spectacular) action as tactical battles are played out on land or sea in real-time. Small but significant changes have been made in every aspect of the game, so while Total War veterans may initially get a feeling of deja vu, the alterations do make themselves more obvious in the long term. The most striking difference is obviously the revamped graphics engine. Empire is without doubt the best looking Total War game yet, with an impressive amount of detail on the wonderfully animated campaign map. Given that here is where you're most likely to spend the majority of your time during a campaign, it was wise of Creative Assembly to put as much time into polishing this part of the game as they did. Units and cities are exquisitely detailed, with wisps of smoke rising from industrial chimneys and the reflections of ships shimmering in the water as fleets glide along coastlines. The game interface has also been refined, allowing easy access to the government, research and diplomacy screens, along with the very handy lists menu, that enables you to hunt down armies or agents with spare movement points with the absolute minimum of fuss. At the tactical level, there are also numerous improvements to the 3D engine, meaning that units are better animated and more detailed than ever before. This all has a cost, however: namely some slothful loading times and a fairly colossal install around the 15GB mark.

That hard drive footprint should give you an idea of just how big the game is. Empire is boldly epic in scale, reflecting the broadening of horizons as the expansionist powers of the 18th Century - such as Great Britain, France and Spain - travelled beyond Europe to colonise the new world. There are three theatres of war, Europe (including parts of North Africa and the Middle East), North America (including Mexico and parts of Central America) and the Indian sub-continent. With over 100 regions and over two dozen nation states (twelve of which are playable), there is not only a huge amount of diversity in military units, but also in the terrain to be fought over, taking in deserts, forests and everything in between.

The battles are intense and highly strategic

All new for Empire is naval combat. This has a very different character from the land-based battles, as unit speed and effectiveness are no longer based on tiredness and morale, but damage levels to the hull and sails. Unit morale is still a factor in naval battles, however, as ships may surrender if too many casualties are taken, or may try to flee the action if they catch fire. Theoretically, fleet engagements are relatively simple affairs. Ships may fire three different types of cannon shot: the classic, large round shot used to damage the hulls of ships; chain shot, which can shred sails to reduce a ship's mobility; and grapeshot, which is best employed at close range to kill enemy crewmen in preparation for boarding and capture. Specialised ships, such as carronade frigates and bomb ketches that carry mortars or other indirect fire weapons, may also be researched and built, adding a further tactical dimension, but on the whole, the key to victory in naval combat is making best use of the prevailing wind and using the correct type of cannon shot as the opportunity presents itself. For example, rather than using a simple exchange of broadsides with round shot until one of the ships sinks, employing chain or grapeshot at an enemy's bow or stern can cripple a ship's ability to manoeuvre, without risking a counter-strike.

Naval battles are perhaps not quite as thrilling as those on land, mainly because the terrain is not as varied or interesting, but it certainly has its moments. The first time you see the gunpowder stores catch fire on a bomb ketch, causing the vessel to disintegrate in a huge fireball igniting any ships unfortunate enough to be nearby, will probably make you leap out of your seat. The naval combat is not without problems, however, as despite the intricate detail of the units, which goes right down to the uniforms on the marines scurrying around the decks, unless you assign units to groups and formations properly, you will end up having to intensively micromanage the battle in order to prevent your units ending up in a scruffy melee, unable to manoeuvre. There is also a fairly comical issue with some of the animation. For example, when a crew abandons ship, the seamen and marines can be seen treading water in perfect unison, like an Olympic synchronised swimming team. So while the naval battles are a welcome change of pace from the strategic map and the land-based battles, they're not exactly an unqualified success.

Visually it's rather impressive, but you'll need a decent gaming rig.

Total War's biggest strength has always been the spectacle of its siege battles and the tactical richness of infantry versus cavalry skirmishes. Here, Empire doesn't disappoint in the least and proves that 18th Century combat wasn't all about the elaborate uniforms and silly hats. With the advent of proper firearms and field artillery, the well-timed cavalry charge is no longer the apex of tactical brilliance, so a lot of what you may have learned in Rome or Medieval II will be undone by the capabilities of the more modern units. Battles are still highly regimented, but now some units can be effective in both ranged and melee combat, rather than only being specialised in one or the other. Recognising when to switch line infantry units over from ranged to melee attacks will help maintain morale and avoid unnecessary losses, and employing the correct unit formation (such as a square formation against a cavalry charge) can also be a critical factor in coming out on top in a battle. New additions to the tactical map, such as fences and stone walls, can provide cover for your ranks of infantrymen and disrupt cavalry charges, giving the player more freedom to fight defensive battles. Terrain is generally less of a factor than it is in Empire's prequels, but canny generals can still make great use of forests to lay morale-sapping ambushes and employ the use of buildings as strong points and artificial high grounds. So with the new features on the tactical map and the shift away from simple horse, sword and bow units to more adaptable cavalry and infantry types, the land battles feel remarkably fresh.

Last, but by no means least, is the strategic portion of the game. With twelve major powers and a whole host of minor nations to compete against, competition for land and resources is fierce, and managing diplomatic relations is a precarious act of juggling competing interests and expectations. Maintaining a prolonged period of peace is difficult indeed, and you have to pick your alliances and trading powers with great care, as currying the favour of one country risks antagonising their enemies. The first twenty turns or so are vital in establishing your burgeoning empire and your chances of achieving your faction's victory conditions. Some factions are easier to establish than others. The Maratha Confederacy in India has one of the best starting points, as you can secure your starting position quite easily by stomping on Mysore right away and then fighting the Murgal Empire to consolidate the entire Indian sub-continent well before the major European powers come knocking on your door demanding land. France and Spain arguably have the most challenging starting positions, requiring early political alliances and expansion into the American or Indian theatre to have any hope of staving off the threat from the other European powers.

A strong economy is essential if you wish to keep the wheels of war well-greased and rolling, so building up your infrastructure as well as your army and navy should be an early priority. Unlike the previous Total War games, the strategic buildings are no longer centralised in a single settlement, but instead spread across each region in towns and cities. While this makes the construction and upgrade of these buildings a little more cumbersome, it does allow players to target parts of an enemy's social or economic infrastructure without having to occupy the entire region - a useful strategy to employ if you don't have the troops to win in a stand-up fight or lay a successful siege, but still want to make a nuisance of yourself. The disruption of trade routes by armies and navies is also another viable method of economic warfare, but does have the disadvantage of tying the fleet or the army to one place while you deny your enemy trade income, leaving them vulnerable to attack.

Chances are you'll be playing this for many months to come

The strategic portion of the game has by far the greatest amount of depth and broadest amount of scope, but alas also has some of the greatest flaws. Graphical flickering of the UI is common but not catastrophic, and some regions (Balestan, for example) fall between theatres on the strategic map, meaning that certain government management screens, such as tax settings, cannot be selected by right-clicking on the Policies mini-map, but instead require you to use the navigator buttons to flick through all the regions you control until it is selected, which can be time-consuming and annoying if you have a large empire. Slightly more concerning is the standard of the AI: minor nations such as Sweden are happy enough to declare the entire civilised world as their enemy, yet the AI-controlled powers seem curiously reticent to wage war on each other. They have no such compulsions about sending in the troops against the player, however, and often do so in a very one dimensional way, sending in armies composed of a couple of units at a time, to be gobbled up by your waiting hordes. Also, while it is possible to demand the surrender of an AI-controlled settlement during a siege, it is rare indeed when the AI will have the sense to do so, rather than force a fight to the death, even when vastly outnumbered and outclassed. These flaws are far from fatal, however, and only slightly tarnish an outstanding game.

Empire is without doubt or reservation the best Total War yet and is a game of unmatched scope and ambition, with its uniquely compulsive blend of turn-based strategy and real-time tactics. It would have been easy for Creative Assembly to stick to the already successful template used in the Total War series so far, but in taking the risk in adding an extra dimension to the game and tackling a more modern era, Empire sets the new standard for strategic wargaming on the PC. While aspects of the game could certainly be improved, Empire demonstrates that PC gaming does not have to compromise or dumb down on detail to be fun or successful. Empire is unashamedly deep, complex and hugely time-consuming, while still being terrifically rewarding aesthetically and mechanically. As long as games like Empire are still being made, PC gaming can look forward to many more years of rude health.