Total Annihilation
"Total Annihilation" was one of the first RTS games to feature radar that showed enemy units within its radius on the minimap. This added an additional element of electronic warfare to the game: players could construct radar jammers that prevented units in a small radius around them from appearing on radar. Mobile radar jammers could be used to create surprise attacks, necessitating the deployment of scout units on a regular basis to reveal said units visually. In addition, radar jammers could disguise the presence of visually cloaked units, such as the commander or land mines. Radar fields rendered cloaked units detectable; a radar jammer could make said units undetectable until the radar jammer was destroyed. "Total Annihilation" was also one of the first RTS games to point the way towards battlefields with hundreds and thousands of units. Previous games could field a hundred units or so. However, Total Annihilation initially permitted 250 units per side which was later patched to 500. A third party patch allowed up to 5,000 units per side.
Empire: Total War
The second major area of gameplay is the battle system. Unlike the campaign game, here players control battles in real-time. As with all titles in the series after "", battles can take place on both land and at sea. However, "Empire" is the first to allow naval battles to be fought in real-time; in previous titles they were automatically resolved by the game's artificial intelligence. Automatic resolution of battles remains an option for both land and sea battles. Separately from the main campaign game, players can recreate individual historical battles in the 18th century and early 19th century.
In land engagements, players have an 18th-century army consisting of units such as cavalry, musketeers, riflemen and artillery. Each has its own intrinsic advantages, disadvantages, cost, and overall effectiveness. Players must use 18th-century tactics and formations to defeat their enemies. The battlefield terrain and the weather are also important. Factions can lay siege to settlements, replacing open land battles with street fighting and close-quarter combat. Each unit has morale, which increases if the battle goes well, or decrease after heavy casualties, army losses, coming under artillery bombardment, or with the death of the general. Tactical situations such as attacking from a flank or the rear, or depriving a unit of allied reinforcements, also hit morale. When a unit's morale is sufficiently depleted, it will be routed and flee the battlefield. Depending on whether morale is merely broken or entirely shattered, the player may be able to rally the unit and regroup. Victory is achieved by causing every enemy unit to rout, or be annihilated. In addition, sieges can be won if the attacker manages to take control of the settlement's central square for a set amount of time. "Empire: Total War" also introduces several new battlefield elements to the "Total War" series. Units can take cover behind walls or in buildings, allowing increased interactivity with the terrain and making some buildings points of tactical importance. Field defences may be constructed on the battlefield. Infantry units can also scale small obstacles such as walls and fences. Each unit has different capabilities such as Square Formation, Wedge, Diamond, Equip bayonets, or Fire at will.