Obstacles

A cavalry, monstrous cavalry, chariot, or shrine model that marches, charges, flees, pursues, or overruns over an obstacle -- or charges an enemy on its far side -- must take a Dangerous Terrain test. Obstacles otherwise don't impede movement; a unit that ends its move straddling one simply places its models on both sides with no ill effect.

An obstacle has a Line of Sight value of 0. A model behind an obstacle and in base contact with it counts as in cover (of the appropriate type) when shot at -- for a unit, the majority of its models must be behind the obstacle to gain this. A firing model that's itself in base contact with an obstacle may ignore it for line of sight purposes, leaning over it to fire.

A unit charging an enemy touching the far side of an obstacle treats the obstacle as "defended" -- measure the charge distance to the obstacle itself, and if successful, move into contact with the obstacle rather than the enemy unit, maximising models from both sides in contact as normal. Models from the charging unit in base contact with the obstacle suffer a penalty depending on the obstacle's type, but only on the turn they charge, not in later rounds. If there isn't room for a rank of chargers to fit between the obstacle and the charged unit, it's fine to temporarily remove the obstacle for the duration of the combat.

Charging a unit behind an obstacle loses all charging bonuses entirely -- no +1 combat result, no lance or similar weapon bonus, and no Impact Hits -- since a charge can't build up any real momentum in such a confined space.

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

Blazing Barricades grant soft cover to units behind them. A unit that completes a charge against a defended Blazing Barricade immediately suffers one Strength 4 hit on each model in contact with it.

Blessed Bulwarks grant hard cover to units behind them, and a -1 To Hit modifier to charging models in contact with them. Models from the Forces of Destruction in base contact with one must also halve their Initiative.

Fences and hedges grant soft cover to units behind them, and a -1 To Hit modifier to charging models in contact with them.

A Ghost Fence grants soft cover to units behind it. A unit defending one causes Fear in the first round of any close combat.

A wall grants hard cover to units behind it, and a -1 To Hit modifier to charging models in contact with it.