Sid Meier's Civilization IV [PC]

One of the last of the turn-based strategy games to survive in the 3D age, the Civilization series allows you to manage the development of a nation from tribal beginnings to the age of spacecraft, nuclear wars, and the United Nations. Whatever the reasons for its continued success, we're not complaining, because the latest in the series is its greatest yet.

To run down the complete list of changes in Civ 4 would take all day. Just about every aspect of the game will be familiar to players of the older titles; there are few totally new concepts. On the other hand, everything from city management to research to troop and resource management has been subtly changed -- depth has been added in some areas, and unnecessary micromanagement removed in others.

It's tough to pick out one change as the most important, but for most players it'll probably be the combat system's differences that make or break the game. No longer do units have different values for attack and defense -- they just have a single strength value, which is modified according to the unit's particular specialties in attack or defense roles. Axeman units get bonuses attacking other melee troops, for example, and archers do well defending cities.

Your units also gain experience as they fight, which can be used to boost their performance in various specific roles. These promotions can actually make an extremely significant -- pivotal, even --difference to the performance of some units. You find yourself far more focused on the strengths of each individual unit, as you can develop a particular squad in a number of different directions You also become more aware of the importance of preserving elite troops and avoiding excessive losses.

These combat changes share the same theme as most of Civ 4's differences: the concepts aren't different, but have added depth that demands more concentration and thought while simultaneously being easier to grasp. It can't have been an easy tightrope to walk, but Firaxis has done an outstanding job.

Adding a couple of new dimensions to the management side of the game, your cities now periodically produce Great People. Half a unit and half a resource, they can be moved from city to city just like any other, but can be deployed in one of a number of ways to produce highly beneficial effects. They can discover new technologies, build special city improvements, join your population to provide ongoing benefits to production, culture, or research, or, in pairs, can be consumed to start a "Golden Age" of increased productivity.

Religion also plays an important role in Civilization 4. A handful of early research topics come with religious discoveries attached -- if you're the first civ to research theology, you'll automatically found Christianity in one of your cities, for example. Religion also plays a role in international relations, and has numerous subtle effects on other facets of gameplay.

Broadly speaking, Civilization's AI has always been strong. Civ 4 doesn't fix what wasn't broken, and the most obvious change you'll notice is that AI civs are now much smarter about accepting and rejecting trades. They also keep track of your behavior, and will hold grudges and remember favors. Lots of factors affect an AI civ's view of you, and, usefully, the interface breaks it all down. You can see, for example, that your +3 modifier from sharing the same religion is offset by that time you wouldn't give them that technology they wanted. Gits.

Visuals aren't usually a big deal for turn-based games, but Civ still manages to be extremely easy on the eyes. It keeps the traditional board game look, with armies represented by an infantry unit, tank, or plane, but battles are accompanied by little animations of your men waving swords, or your planes dropping bombs. It's clean, smart, and attractive, and that's all it needs to be.