When firing upon a unit, there are two factors on top of "base-chance-to-hit", that determine whether a hit is successful. These are:
- The distance to the target
- The target's height
Not only is a small unit harder to hit, but a shot generally needs to be aimed lower or it will pass over the head of a short unit. For example, you can fire over the top of your tank and hit units on the other side. A shot can pass under a unit which floats above the ground, in much the same way.
Height also affects visibility of units in the Battlescape. Shorter units such as Sectoids can be difficult to detect even at short ranges if they are standing in fields of tall crops.
The following table lists the heights of each unit. While all units have a separate height when kneeling, only the solder can actually perform this action.