Many have since complained - how can a knight shoot a gunship out of the air? How is this possible?
What people fail to understand is the sheer scale on which the civilization games occur. Each turn in the game, depending on the nature of the scenario, usually covers a number of years. In a regular game this period is as much as fifty years early on, reducing to a single year around the 20th century.
Furthermore, the individual units we're seeing in the game, and the squares they occupy, are on a very large scale as well. Even on a 'huge' sized map for instance, a landmass as big as France is only 5 or 6 squares across (as you can tell from any 'world map' scenario). In reality France is just under a thousand kilometers across, making each square around 100-200km wide.
So when you have a 'gunship' unit attack a square occupied by a 'knight' unit, we're not just seeing a single battle take place. Its not necessarily like Lord of the Rings where two opposing armies line up and decide to make a day of it.
What we're really looking at is a prolonged campaign between two opposing armies, possibly over a number of years. Take the infamous example of the Vietnam War. Even with tanks and gunships, the Americans weren't able to quell resistance from an army of Vietnamese peasants often little better equipped than a band of medieval knights would be. The Soviets learned a similar lesson in Afghanistan.
Going back to the units in Civ 4, we can see that each unit in the game represents a large army acting over a number of years. The issue of just how big these armies are is one fans have debated as long as Civilization has been around. Does one 'knight' unit represent a thousand fighting men? Ten thousand? Fifty thousand?
And even if you can decide on a number, do the different units represent an equal commitment of men? If a 'swordsmen' unit represents ten thousand swordsmen, then does a 'tank' unit represent ten thousand tanks? What about a battleship then?
Clearly this couldn't be the case. Units gradually increase in strength and cost as the game goes on. In Civ 4 a medieval knight has 10 strength, while modern infantry have 20. Gunships have 24, while the most powerful unit - a 'modern armour' has 40. Presumably part of the difference in scale is that modern units represent somewhat fewer fighting men or machines relative to older units.
So when we see a gunship attacking a knight, we're not looking at ten thousand knights lining up in a grassy field one morning to get slaughtered by ten thousand gunships. What we're looking at is a group of -lets say ten thousand- knights defending a region of territory over a period of many months or years against an attacking group of say, a few hundred gunships.
While they're in the air, the gunships would be just about invincible to the knights, but aircraft are going to spend at least 90% or so of their time on the ground. The knights could dismount their horses, disguise themselves as local civilians, attack the gunship base at knight, and attempt to hack their way through the guards and sabotage the machines.
Of course, under such circumstances, the knights are still the underdogs - but that is exactly what the game is trying to reflect. They face a difficult fight, but not an impossible one, and occasionally they're bound to get lucky and catch the gunship crews off-guard.
