Models that are subject to Stupidity are also Immune to Psychology – they just don't get frightened that easily, and by the time they do, it's normally too late.

Provided that they are not engaged in close combat, a unit that contains one or more models with the Stupidity special rule must try to overcome its Stupidity at the start of its turn by taking a Leadership test. If the test is passed, all is well – the creatures have risen above their dull-witted nature and will act normally. If the test is failed, the warriors succumb to their stupidity and amble forward, perhaps drooling a little, eating grass or cackling in silly voices, as explained below.

Me 'Ead 'Urts

A unit that fails its Stupidity test immediately stumbles D6" directly forwards – this move is otherwise treated in exactly the same manner as a failed charge. The Stupid unit cannot take any further action that turn, so cannot declare charges or make a shooting attack. Wizards that have failed a Stupidity test cannot attempt to cast or channel power dice or dispel dice until a Stupidity test is passed (there's a lot of hand waving and chanting, but for some reason the magic just doesn't seem to work).