Over the ages, gaming systems have invented many systems for picking a random direction using dice. Numbered templates, lookup tables of compass directions, numbers printed on bases, assigning numbers to hexes. All these systems have the same flaws - they're clumsy, and only allow a limited number of directions to be chosen. Like the dice, they're digital. This isn't a problem in some games (in Battletech played on hexes, for example, only six random directions are needed), but for many games played with miniatures, the exact position of the miniatures matters, and a finite number of directions is insufficient.

In adeptus titanicus, random directions were chosen by rolling a d6, and consulting a compass on either the base of the titan. It was possible to manipulate this method to obtain an unfair advantage - if two friendly titans are positioned line abreast, an incoming barrage fired at one will never scatter sideways and hit the friendly titan, only 15 degrees either side. In Space Marine, the same 'compass' system was used, but the compass was printed on a 'deviation template'. North always pointed towards the model calling the barrage, so by careful choice of spotter and position, it was possible to maximise the number of potential targets should the barrage scatter.

To counter this problem, in the revised edition of Space Marine (which unified Space Marine and Adeptus Titanicus), Games Workshop introduced the scatter dice. A scatter dice is 3/4 inch D6, marked with 4 arrows, and 2 hit symbols. The dice is used by throwing it somewhere near where a random direction is needed. Wherever the arrow points is the direction. This is truly analogue, and so impossible to exploit in the way that the older 'compass' method could be. The 'hit' symbols have small arrows built into them, so that the dice need not be rerolled if a hit comes up but a direction is needed.

The scatter dice is one of these 'I could have thought of that' ideas - it seems very obvious after seeing one, but for decades gaming systems have used table-based methods that are less powerful, and less intuitive. The Scatter Dice is patented, and aggressively defended by Games Workshop.