Bolt or dart throwers are large crossbows which shoot a spear-sized missile. They are so large that they are mounted on their own stand, often with wheels so they can be pivoted easily. A crew of two or more is required to wind back the powerful torsion arms and position the huge bolt ready for firing. On the whole these weapons are nowhere near as large or cumbersome as stone throwers and cannons.
Bolt throwers are fired in the shooting phase along with other missile weapons. To shoot your bolt thrower first turn it on the spot so that it points towards your intended victim. The bolt travels straight forward and (hopefully) hits the first target in its path. To determine if the bolt strikes its target roll a D6 to hit using the crew's BS in the same way as bow shots, crossbows, and other missile weapons. The basic score needed to hit is therefore shown on the standard Missile Fire Chart (below). The usual modifiers apply, see the Shooting section and the play sheets for details.
If you score a hit work out damage as described below. If you miss then the bolt hits the ground or sails into the air and comes down harmlessly somewhere else.
Missile File Chart
The chance of a shooter scoring a hit on his target depends on his ballistic skill, or BS. the higher the individual's BS, the greater his chance of hitting. To determine whether you hit you must roll a D6 for each model shooting. Count how many models in your unit are shooting, and roll that number of dice. It is easiest to roll all the dice at once, although you don't have to do so. If you have a lot of models shooting you may have to roll several batches of dice. The following table shows the minimum D6 score you will need to hit.
If you score at least the number required you have hit, if you score less you have missed.
For example: You fire with 5 Goblin archers. Goblins have BS 3, so you need a score of at least 4 to hit. You roll 5 dice and score 1, 2, 2, 4, and 6 - 2 hits and 3 misses.
Of course, you cannot roll less than 1 on a D6, so troops with a BS of 6 or more will invariably hit. However, circumstances can make it harder to hit as described below, and this may increase the dice score required so that even troops with very high BS values can find it difficult to hit their target.