Models that are wounded still have a chance to avoid damage if they are wearing armour or carrying shields, or if they are riding a horse or similar creature. These models have an armour saving roll.
Roll a D6 for each wound suffered by your troops. If you roll equal to or greater than the model's armour save, the wound has been deflected by its armour.
For example, a warrior carrying a shield and wearing light armour bas an armour save of 5+, so he must roll a 5 or 6 to be saved by his armour.