Use this Stratagem in any phase, when a PRIMARIS unit from your army is selected as the target of an attack. Until the end of the phase, each time an attack is made against that unit, an unmodified wound roll of 1-3 for that attack fails, irrespective of any abilities that the weapon or the model making the attack may have. If that unit contains 5 or fewer models, this Stratagem costs 1CP; otherwise, it costs 2CP.