Plains come in three categories: farms, grasslands, and battlefields. Farms are common in settled areas, of course, while grasslands represent untamed plains. The battlefields where large armies clash are temporary places, usually reclaimed by natural vegetation or the farmer's plow. Battlefields represent a third terrain category because adventurers tend to spend a lot of time there, not because they're particularly prevalent.
The table below shows the proportions of terrain elements in the different categories of plains. On a farm, light
undergrowth represents most mature grain crops, so farms growing vegetable crops will have less light
undergrowth, as will all farms during the time between harvest and a few months after planting.
The terrain elements in the table below are mutually exclusive.
Undergrowth: Whether they're crops or natural vegetation, the tall grasses of the plains function like light
undergrowth in a forest. Particularly thick bushes form patches of heavy
undergrowth that dot the landscape in grasslands.
Light Rubble: On the battlefield,
light rubble usually represents something that was destroyed: the ruins of a building or the scattered remnants of a stone
wall, for example. It functions as described in the
desert terrain section above.
Trench: Often dug before a battle to protect soldiers, a
trench functions as a low
wall, except that it provides no
cover against adjacent foes. It costs 2 squares of
movement to leave a
trench, but it costs nothing extra to enter one. Creatures outside a
trench who make a melee attack against a creature inside the
trench gain a +1 bonus on melee attacks because they have higher ground. In farm terrain, trenches are generally irrigation ditches.
Berm: A common defensive structure, a
berm is a low, earthen wall that slows
movement and provides a measure of
cover. Put a
berm on the map by drawing two adjacent rows of
steep slope (described in
Hills Terrain, above), with the edges of the
berm on the downhill side. Thus, a character crossing a two-square
berm will travel uphill for 1 square, then downhill for 1 square. Two square berms provide
cover as low
walls for anyone standing behind them. Larger berms provide the low wall benefit for anyone standing 1 square downhill from the top of the
berm.
Fences: Wooden
fences are generally used to contain livestock or impede oncoming soldiers. It costs an extra square of
movement to cross a wooden fence. A stone fence provides a measure of
cover as well, functioning as low
walls. Mounted characters can cross a fence without slowing their
movement if they succeed on a DC 15
Ride check. If the check fails, the steed crosses the fence, but the rider falls out of the saddle.
Other Plains Terrain Features: Occasional trees dot the landscape in many plains, although on battlefields they're often felled to provide raw material for
siege engines (described in
Urban Features).
Hedgerows (described in
Marsh Terrain) are found in plains as well. Streams, generally 5 to 20 feet wide and 5 to 10 feet deep, are commonplace.
Stealth and Detection in Plains: In plains terrain, the maximum distance at which a
Spot check for detecting the nearby presence of others can succeed is 6d6x40 feet, although the specifics of your map may restrict line of sight. Plains terrain provides no bonuses or penalties on
Listen and
Spot checks.
Cover and
concealment are not uncommon, so a good place of refuge is often nearby, if not right at hand.