Courage

Courage is part of the main stats, also called SPECIAL-Co values.

In these rules it's usually abbreviated with a simple "Co". Do not confuse it with Charisma, which is abbreviated with a single "C".

Courage is the stat that indicates how easy it is for your character to endanger his (or her) body. Courage is therefore used for the skills tactics, driving (engines), riding, climbing, acrobatics and body control and also decides if your character will take a big risk.
Courage is therefore the most important stat.