Originally Posted by Alex Walz
You can make both single-player and multi-player scenarios and campaigns. I'm not too familiar with the Total War gameplay, so you'll have to elaborate before I can make a comparison.
The player takes a role equivalent to the head of one the three great Roman houses at the time; the Julii, Brutii, and Scipii. Each of these factions has a different set of attributes and initial objectives. After a winning campaign as Romans (or using a simple mod) it is possible to play with other factions and take on a role similar to that of Hannibal, the brilliant Carthaginian general during the Second Punic War or the Gallic warlord Vercingetorix. Gameplay consists of a combination of turn-based strategy and 3D real-time tactical battles. The 3D real-time action is uniquely different from most standard RTS games in that tactical maneuvering is critical to success whereas most RTS games take no account for the direction units are facing, flanking movements, breaking of lines, etc. The tactical module addresses the criticism of unrealistic mutual blood baths in other RTS games (units will "rout" in Rome: Total War). The high-quality 3D graphics engine is able to render over thirty thousand men on a single battlefield. The strategic and tactical modes integrate such that the landscape for the battles is the same as seen on that particular spot on the strategic map where the armies meet. Each unit has its own type, stats, armour, weapons, and upgrades.
The game is similar to its predecessors, Shogun: Total War and Medieval: Total War, although there are some changes to the mechanics of sieges and city fights have been added. Most notable is that players now move their units with movement points; in previous games units were moved by territory.
Armies can be built to conquer nearby provinces; to conquer a province, you must capture its settlement. Fleets at sea can also ferry troops, and blockade enemy ports, thus cutting down income from trade. While doing so, players can build certain buildings within their cities to move up through the tech tree to train more advanced units, increase a province's income, and/or keep the population happy. The ultimate goal is to conquer 50 provinces and capture Rome, thereby becoming Emperor.
(copyed and pasted from the rome total war Wikipedia page)