Some spells have saving throws that take the form of rolling a dice requiring a score lower than one of the unit's or model's characteristic values. Which characteristic is used varies from spell to spell - Movement or Initiative might be used to dodge out of the way of an attack, Strength to break out of a binding enchantment, Toughness to survive a magical plague, and so on. The number of dice rolled and the characteristic used are specified on the spell card.

The card also specifies whether you need to roll under the characteristic or equal to or under the characteristic. It is very important that you read the card carefully to find out which is the case as just one point difference often determines whether a model lives or dies! If the spell affects a whole unit make one roll for the unit on the troopers' characteristic value; character models accompanying the unit roll separately using their own characteristic value. Most rolls are made with a D6. Note that on a D6 roll of 6 the test is always failed regardless of the characteristic score.