Hitting a target.

Hitting a target is determined by the size of the target. Some creatures are small, and therefore hard to hit. Whereas others are large and easier to hit. Note that different creatures may have to roll different to hit scores, but all playable races abide by the same rules when it comes to hitting.

Swarms:
A single enemy from a swarm poses little threat, however swarm enemies always travel in large numbers, making them a large and easy target, but also making them dangerous. A score of 20 is required to his a swarm, but for every creature in the swarm, the score required to hit is reduced by 1. As such, a swarm of 10 snakes would only require a score of ten to hit, given that a large bundle of snakes is easier to hit than a single one.

Ankle biters:
Small enemies like sandsharks are incredibly hard to hit, given their fast movement and tiny size. Ankle biters travel in packs, but unlike swarms, they keep spaced apart enough to benefit from freedom of movement, and present as a spread fomation rather than a large target. Ankle biters require a score of 15 to hit.

Human sized:
Anything from Drall size to large human fits into this catergory, and it can generally be classed as any droid or bipedal creature. Human sized opponents require a score of 10 to hit.

Large creature:
Most commonly found in forests and highly hostile area's. Large creatures are easy to hit, and classed as anything that a human sized creature would be able to ride. Large creatures require a score of 5 to hit.

Enormous creatures:
The stuff myths are based around, these gigantic beasts are exceedingly rare, but their sheer size means that even a blind man could hit them. Enormous creatures are hit on a 2 or higher, meaning anything but a critical fail will hit them. A prime example of an enermous creature is the leviathan.