Terrain is an area of land including the particular features of it. In CM, terrain includes everything that you can see in the game except units; thus, buildings and "flavor objects" such as tires and carts are counted as terrain even though in the real world they are part of the built environment. All terrain in Combat Mission is known to both sides at setup time; "unknown" terrain including such otherwise great ideas as hidden bunkers is not possible. An experienced player can virtually "walk" the battlefield and get a good idea of which positions can see which.
There are many specific kinds of terrain in CM, but they can be grouped into several large sets. Generally, what the CM player cares about for terrain types are the following questions:
- does it block line of sight?
- does it provide cover and concealment?
- what units can I move through it? Infantry can enter most but not all terrain; vehicles are considerably more limited.
Elevation is the height of the surface of the ground. Although certain terrain types come with built-in tweaks to their local elevation, in general one can think of CM elevation as independent of its overlying terrain.
The elevation of terrain has a powerful effect on combat mainly by its effect on line of sight. Even a small elevation dropoff can place many meters of dirt in between two units, thus completely precluding direct fire. Or similarly, even a meter or two of elevation can allow a unit to see a great distance over low concealing terrain such as fields of wheat.
Buildings always provide good concealment for infantry, and many buildings also offer significant cover. In addition, most buildings offer nearly perfect cover for infantry when they are hiding. Vehicles cannot enter buildings in any CM game.
There are two kinds of buildings in CMx2: "independent" buildings and "modular" buildings. (These labels are what the Map Editor uses.)
Independent buildings are various types of special buildings (commercial storefronts, barns, etc.) designed specifically for the Normandy setting. As the title implies these are intended to be used as independent buildings. "Church" is available as a small country church or in three "building blocks" that can be used to create a large cathedral. Generally, independent buildings offer poor cover, although the churches are an exception.
Modular buildings are more generic building blocks (ranging from 1 to 8 stories high) of varying sizes and configurations, and can be used by map designers to put together large building complexes, cities and other structures. Modular buildings offer significant cover.
There is a good overview of building types in Normandy featuring lots of picture found at the forums.
"Ground" is the term we use to describe any of a great variety of ground types plus the plants (if any) which cover them. Thus mud, wheat, and grassXT (extra tall grass) are all types of ground. Each action spot has just one kind of ground, which typically covers it uniformly.
Generally, ground terrain types offer no cover, and poor concealment, although some have high enough plant growth to offer concealment to prone men. Most ground types can are passable to all units, with the exception of heavy forest, which only infantry can enter.
Here the "surface" of the ground is water.
- Marsh - infantry only.
- Water - impassable to all units except at fords.
- Deep Ford - infantry only.
- Shallow Ford - all units allowed. Large chance of bogging.
Roads and Bridges
There are many kinds of roads available in the game. All units can use them and they always have a smaller chance of bogging than other ground terrain types. However, testing at the forums shows an increased chance to bog for at least some tanks when the tank is partly on a road. Thus, when you use a road you should give precise orders to keep your vehicles on the road.
There are four kinds of bridges, as follows:
- Footbridges - infantry only.
- One lane stone bridges - all units except heavy vehicles can cross.
- Stone rail bridge - all units except heavy vehicles can cross. Testing has shown that vehicles can't (or perhaps won't) go under it, but infantry can.
- Two lane stone bridges - all units.
CMx2 supports various man-made barriers that stick up from the ground significantly, creating two sides. Although two-sided terrain fill the action spot, there is no choice of the ground cover for the flat parts: you get low grass.
The thicker kinds excellent cover and concealment for fire which crosses the barrier. All wall-like terrain can be blasted to allow traversal. Most wall-like terrain with the can be destroyed by nearby high-explosive hits, and this is commonly seen for all types except bocage.
- Hedgerows (Bocage) - Two kinds, high and low. Impassable to all units, except tanks with rhinos (which plow their own holes). Infantry can pass via small gaps which are rather hard to see. Can be destroyed by ordinary HE, but it takes a lot of it. Infantry with demo charges can blast holes. The only difference between high and low bocage is their effect on blocking line of sight: high bocage is higher. Low bocage is, unfortunately, rather hard to distinguish from hedges, even though the two are radically different in the game.
- There is a very good primer on bocage at a Few Good Men. It shows the different types, how close infantry and tanks need to be to see through, and how to identify a rhino-equipped tank.
- Tall walls - impassable to all units. Good cover, perfect concealment.
- Low walls - infantry jump over. Impassable to wheeled vehicles. Other vehicles break them down (removing them completely) at a small risk of immobilization. Low walls offer good cover and some concealement so long as they remain un-blown up. For prone infantry, they offer perfect cover and concealment.
- Hedges - movement effects like low walls, but offering very little cover. Good concealment, especially when prone.
- Fences - like a hedge, but little concealment.
Foliage includes brush, trees and bushes that rise significantly above the ground. Trees create small cover. All foliage creates moderate concealment (although usually they have also good concealment terrain as their ground). Foliage creates significant blockage to line of sight.
Flavor objects are typically man-made items which exist on the battlefield. As their name suggests they do not do very much (although they do offer a small amount of cover and concealment, and so men will cluster behind them). Mostly they exist to allow mapmakers to give the battlefield a realistic "lived-in" appearance.