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I am playing lizardmen in one week and i was going to take lore of metal (just for spirit of the forge) and i was wonderering whether scaly skin is counted as actual armour or not.
What do you think?
its strength is based on the armor save of the model - so yes
Yeah there aren't rules for different classes of armour, so armour is armour. Scaly skin is an armour save so follows the normal armour rules. In the same way the additional save from being mounted on a horse or chariot would be effected like normal armour.
Scaly Skin doesn't count as armour, its a special rule. But Scaly Skin saves do add to a models armour save, so it does count towards the effect of Rule of Burning Iron.