Rivers

For Line of Sight purposes, treat rivers as open terrain.

The weight of the water makes it impossible to march through a river -- movement is otherwise unaffected.

A unit at least partially in a river can never gain rank bonus -- the footing is too treacherous.

A bridge, ford, or similar crossing point is normally treated as open terrain, but only for a unit in a narrow enough formation to actually fit across it -- otherwise treat the whole unit as being in the river instead.

A few examples of rivers follow, using the rules above unless stated otherwise.

Any model at least partially in a Boiling Flood at the end of any turn suffers a Strength 4 hit with no armour saves allowed. Models immune to Flaming Attacks are unaffected.

Necrotic Ooze counts as dangerous terrain for every model. A unit that moves through it also gains the Poisoned Attacks special rule until the end of the following player turn.

A Raging Torrent is dangerous terrain that causes a failed Dangerous Terrain test on a 1-2, instead of just a 1.

A unit that moves or charges through a River of Blood causes Fear until the end of the following player turn.

When a unit enters a River of Light, it's immediately the target of a randomly chosen Light Magic spell -- automatically cast and impossible to dispel. If the spell has a choice of casting values, it's assumed to be cast at the lower one.