In order to shoot at something, a model must be able to draw a line of sight to it. Often, not every model in a unit will be able to draw a line of sight to the target. Therefore, when shooting with a unit you must determine line of sight for each and every model in the front rank. Normally, only models in the front rank of a unit can shoot. However, sometimes the rules will allow models in the rear ranks to shoot. In such cases, models in the rear ranks are able to see what the model at the front of their file can see.