RTS Basics - Units

One of the major philosophies of unit design is paper- scissor- rock. Unit A counters Unit B, B counters C, but C counters A. Each unit has its own strengths and weaknesses, so there will always be some Achilles Heel to any unit or strategy you care to use. Players are encouraged to use combinations of units, rather than just one type. Each unit will have its own strengths and weaknesses, and knowing where and when to take advantage of them pretty much forms the heart of most of your military tactics on the field.

Swordsmen can be seen as melee units, or units that fight hand to hand. They have to stand next to their target in order to attack it. Archers can be seen as ranged units, or units that can shoot over a distance. Archers may be quickly killed in hand to hand fighting with Swordsmen, but long before Swordsmen can reach them they'll be turned into human pincushions. Range becomes the winning factor. For all their strength, melee units will die like flies to an enemy that can use range against them.

However, up against enemies that are fast on their feet, range starts to look lose its effectiveness. Cavalry can fly like the wind: Archers might be lucky to get a shot off before the horseman have swept through them and put many to the sword. Speed is the winning formula here. Looks like the Cav has the ultimate trump. But...

Pikemen are chaps who brandish a very long pole with a sharp point. They're not very fast, don't have any range, get pincushioned by Archers, and have difficulty keeping Swordsmen at bay. But against Cavalry, suddenly those long pikes are skewering fast moving knights left, right and centre. Well, well. The Pikeman is a counter to the cavalry unit. Its also a defensive unit, one that can defend well against enemies but isn't terribly good at attacking themselves. Defensive units are not put into your army to increase its destructive power, but more to help it cope against counter-attacks from the enemy.

Each unit has a special skill or attribute that sets it apart from its fellows. It may be as simple as a light, cheap, all-purpose grunt, or a specialised counter measure that is only useful in certain situations. Whatever its capabilities, their functionality determines the way you use them.

Probably the best way to handle units is to think of them as ensembles rather than a collection of individuals. That is, they work better in different combinations than just an army made up of the one type. Each type performs a role and fills a vacancy in your force's requirements. No one unit will be the ultimate enemy killer - different combinations used on different occasions will be. In other words, there's no one way to win a RTS game, and playing the same map under the same conditions with the same foes can result in lots of different victories (or defeats!). Mixed forces that combine different theatres (i.e. air, ground, sea) are going to be far more effective than just the one type alone. Big rushes with only one type of unit are usually inadequate unless you're exploiting a known weakness somewhere. The only drawback with a large mixed force is the difficulties in coordinating everything. Different units travel at different speeds and your guys will become scattered across the map when they travel. But most games have many features that can help you there. (See Being in Three Places at Once.)

Unit trumping can also occur if units occupy different theatres. By theatre I mean the domain a unit travels and fights in, e.g. land, sea or air. A plane can attack anything on land or sea, but may not see or affect submarines; a ship may bombard coasts, hunt subs or shoot down aircraft but can't reach deep inland; a submarine can torpedo anything in the sea but can't affect land units. Fairly obvious, really. Planes, tanks and submarines all occupy different theatres of operation. In their "native" realm they're at their strongest, but outside they can become completely vulnerable to attack.

Paper - Scissor - Rock goes beyond unit to unit struggles. Once you start getting groups of units together, or start working with different combinations of them, then the possibilities start to increase rapidly. A pathetically weak unit may suddenly become devastating if it turns up in numbers, or has companions who can protect it and allow its special abilities to be unleashed.