My Tau Codex features a strategy rating. I've not seen this before. What is this used for?
3 Answers
It was part of the basic scenario and campaign systems in the core rulebook back in 3rd and 4th editions. It was dropped in 5th edition on. Each race used to have a strategy rating that would give you the ability to chose which scenario to play. Even when it was part of the rules, I seldom saw it get used.
You don't loose much by not being able to use it anymore.
According to several forums I checked, strategy rating is an obsolete mechanism used in certain published scenarios that would typically give some kind of advantage (initiative, timing of reinforcements, etc.) to the side with the higher strategy rating:
It used to affect which side got to move first. You both rolled a D6 and added your leader's strategy rating. The highest total got the first move.