Used to modify the cost of bridging such a river type. The base cost is specified in bridge.
You can use 6 sprites for each direction one or 64 sprites (just as with the landscape x64 borders)
If no bridge is present over the river the following AP penalties will be added for any move type attempting to cross it.
If no bridge is present these penalties are brought to bear on the individual attacking over the river as long as it has not broken through. This value is NOT a modifier but the ammount that the attackers hitpoints are diminished… so 0.4 means -40% and 0.8 means -80%. If a bridge is present the penalties are lowered with rulevar 5.