Resistance
Resistance is a secondary skill that increses the magic resistance of hero's troops.
Thorgrim the ranger is the only hero that specializes in resistance.
Comments & debate
It is a common misconception that Garniture of Interference, Surcoat of Counterpoise or Boots of Polarity would increase the resistance secondary skill in a similar way that for example Bow of Elven Cherrywood increases the archery skill. However, this is not the case. The "resistance artefacts" increase the magic resistance of creatures, as does the resistance skill itself. Basically this means, that wearing any of those artefacts gives the magic resistance bonus with or without the resistance skill.
Resistance is might be useful in scenarios with lot of battles against AI heroes or in multiplayer games.