On the battlefields of Advance Wars, there are many different kinds of terrain. It plays an important part in battles, as each kind of terrains have a different effect, such as giving a defense bonus, reducing visibility, concealing a unit or impairing mobility.
Terrains' effects can further be changed through a random game mechanic called Weather.
Each type of terrain has a defensive rating ranging from 0 to 5 stars. The defense of the unit stationed on that terrain will be increased by 10% per star. This bonus is vital in every battle and should be taken into account when moving your unit. Terrain defense can determine how much damage the unit defending receives, and how much damage it can retaliate in return.
For example, given no CO bonuses are in play, an Infantry standing on a road which gives no defensive cover being attacked by another Infantry will receive 65% damage. In contrast, an Infantry stationed on a mountain, which provides 4-star defensive cover, will only receive 33% - almost half the damage was it to be placed on a road.
Lash can double the terrain defense stars using her Super CO Power.
The range in which units can travel may also be affected by terrains. When checking terrains' detail using the L button, several numbers corresponding to each movement type will indicate how much movement points are needed to cross that terrain. 1 means the unit can move over that terrain unrestricted, 2 means that the unit will need to spend 2 movement points to cross that terrain, and 3 means that 3 movement points are needed.
Only Infantries and Mechs can travel through mountains and rivers, in which the latter unit has unrestricted movement. Air units can travel on all terrains unhindered. Some COs have special abilities or powers to reduce the movement points needed to move across each terrain.
When Fog of War is enabled, some types of terrains are granted more effects. Each unit has a designated range of vision, and some terrains can increase or reduce it, or hide the unit from the enemy's view completely.
Placing Infantry or Mech units on mountains will increase their vision range from 2 tiles to 5 tiles, allowing you to keep tabs on your opponents while your unit is relatively safe.
Vision will also not directly apply to woods, reefs or sea fog. They will always remain covered with FoW unless there is a friendly unit next to it. This effect provides several advantages: placing units in such tiles effectively makes them invisible to the enemy until they place a unit next to it, allowing you to move units unseen and conduct surprise attacks or retreat safely under the FoW, while your enemy needs a unit to spot your unit, and another one to actually attack it.
There is also the danger of ambush. An ambush occurs when a unit moves across a tile which is already occupied by a previously unseen enemy unit. The moving unit automatically stops and cannot take orders for the rest of that turn. Even when you are only planning your movement but have not yet confirmed it, an ambush can still occur. This makes for a risky manoeuver when unaware of enemy positions.
It should be noted that a few aesthetic features may give away some information. Battle animations will display which type of terrain the attacking unit is stationed in. Through knowing which terrain they're hidden at, indirect units and submarines can be revealed this way. Similarly, when units move, a different sound is played depending on what type of unit they are, as well as where they are moving from and where they ended up. Units passing through opponents' field of vision are also revealed through a brief glimpse, even if that unit ended their turn out of the opponents' vision.
In Days of Ruin, the Flare unit allows you to shoot a limited amount of flares across a certain distance, making an area of two tiles around the target completely visible, including terrains previously obstructed.
List of Terrains
|Laboratory/Communications Tower (Mercenary units)||x||x|
|Communication Tower (army boosts)||x|