Cry havoc and let slip the dogs of war!
Our last experience with Rome: Total War dealt only with multiplayer. This time, we got to the traditional heart of the series, singleplayer mode. The player is initially limited to the three playable Roman factions - the Julii, the Brutii and the Scipii. Each faction that the player conquers is unlocked and becomes playable in the next campaign. Given the vast distances between the Britons and Seleucids, plus the competition with the other two Roman factions for conquest, it seems that it would take several campaigns to unlock all playable factions.
The Julii were my choice, perhaps out of a desire to recreate Julius Caesar's campaign. For the most part they end up fighting Rebels, Gauls and Germans - at least for the early part of the game. Other likely enemies include the Britons and Spaniards. These foes are really pretty much your standard barbarians. They'll have a unique unit or two but for the most part aren't as well-equipped and developed as, say the Carthaginians or Greeks would be.
On the other hand, the Gauls have a huge swathe of territory to draw resources from. While the cities don't seem to have developed very well (not that I could compare against Carthago or Alexandria), they are very numerous and have a ton of manpower. The three provinces the Julii start with and the two easy Rebel conquests could not compete on resource terms with the Gauls, so the early Roman battles are won with technology and superior leadership.
The strategic AI is actually very impressive. It gathers armies of at least equivalent strength before attacking the player and often sends much bigger formations into combat. I routinely faced 2:1 odds on the field and on a few occasions had to fight desperate city defenses against three times as many foes. The enemy AI also makes good use of ambushes on the strategic map.
Now to understand an ambush, you need to know that the strategic map has been completely changed. It's now fully 3D, and the forests, mountains, hills, rivers and roads you see on it will appear in your battle maps. Units like armies, diplomats and spies have limited freedom of movement, depending on terrain, on this map. Each unit has a set number of movement points and you are no longer guaranteed to cross an entire province in one turn, never mind get to the enemy city. Not only that, but armies can lie in ambush on the map, stopping their movement early and preparing an attack on their enemies. Should you blindly set a long marching order into unknown ground, it's quite possible to stumble into one of these surprise attacks.
An ambush is a nightmare of a tactical battle. The enemy starts off prepared to the player's forces and very close. There's no possibility of deployment and, to make matters worse, the player's formations are in marching columns rather than battle order. Thus, they are long, thin, facing the wrong way and with their flanks completely exposed. Combine this with the fast pace of combat in Rome, and you are truly lucky to survive one of these attacks.