Terrain not allowing units to move ?

[CizmOne]

New player here. Just started a new campaign. Can't move units on Marsh Grassy terrain 2 hexes from Capital. Very first turn. Why ?

[Xxzard]

Most likely, the unit you are trying to move does not have enough Action Points (AP) to move there. Marshes have high AP cost for wheeled and tracked vehicles, and higher than baseline cost for infantry.

To get detail on why, select the hex, then hover your mouse over the little picture of the terrain in the bottom right. You can see a table of the AP cost for all unit types to move into that hex, and other factors such as rivers also affecting movement costs.

Generally speaking, sand dunes, marshes, and forests are more difficult for wheeled and tracked vehicles to traverse compared to infantry. Hills are also difficult. High Mountains are impassable for wheeled and tracked vehicles without roads.