How Terrain Affects Movement I : Edge Effects

Many types of physical features on the wargame tabletop have the property of halting and/or reducing the movement of combat pieces. These features are collectively called “Terrain” and generally fall into one of two broad classes: Edge Effect and Area Effect. A small number of terrain features (Composite Effect) have some or all of the properties of the main two. This post will deal with the first main type.

Edge Effect Terrain is a feature that stops movement (and ends the current action) when a combat piece contacts it. In most cases a new action must be expended to cross over the edge effect feature.

Many edge effect terrain features represent common vertical obstacles. The two most common are shown below:

Edge Affect - Vertical

To the left is a hedgerow and on the right a stone wall. These may be represented in different ways on the tabletop, with variations in height and width, but all have the same effect.

Water Obstacles (if they are not marked as impassable) are also edge effect terrain features and halt movement when a combat piece encounters their edge:

Edge Affect - Flowing Water

A Stream (a water obstacle less than the width of a combat piece) is show on the left and a River (greater than the width of a combat piece) on the right. The river obstacle is a Composite Effect Terrain feature that contains both an Edge Effect and an Area Effect. Area effect will be discussed in a following post.

Composite Effect Terrain does NOT require the expenditure of an action to cross it (since an area effect will be applied to the next movement action) but in the case of a river the opposite bank ALSO acts as edge effect terrain and requires the combat piece to stop and lose the remainder of its action.

A typical  movement sequence involving Edge Effect Terrain is shown in the photo below:

Edge Affect - Crossing

In Action One, a combat piece contacts the edge of a stream and must stop (losing any remaining portion of its movement). A green star is placed as a reminder that the piece (or unit) has already paid the movement penalty if a second action is not used in the same turn to cross the obstacle.

In Action Two, a combat piece crosses the stream and is placed with the rear of the piece touching the opposite side. The expenditure of one action represents the time and energy required to climb over or pass through an obstruction.

In Action Three, normal movement resumes.

The third type of edge effect terrain is Elevation. An Elevation Line marks the beginning of elevation (a hill or ridge) on the wargame tabletop and acts as an edge effect obstacle when encountered from the lower side:

Edge Affect - Elevation

Since elevation is a composite effect terrain feature, no action in required to cross over the elevation line, movement limitations being imposed after crossing.

Not all joins between areas on the tabletop represent elevation lines. An elevation line exists only where rising terrain lies beyond it (as in the picture above). Elevation lines are determined by either marking on scenario maps (usually with orange lines) or by mutual agreement of the players at the beginning of the game.

Next – Area Effect Terrain

2 thoughts on “How Terrain Affects Movement I : Edge Effects

Comments are closed.