Well, RRtK is the new version of the old Warrior Heroes ruleset. If you have it then you know how RRtK works. In case not I can tell you that in RRtK each stand represents one body of troops like in DBA. Stands stats are Rep, armour and special abilities, and the number of miniatures on each stands count for movement and melee purposes; the more figures the slower to move but with more possibilities to outnumber the enemy.
Stands or units are not destroyed by a combat result but suffer hits which are cumulative and affect negatively the unit's Rep in order to pass reaction tests. whenever the unit totally fail a reaction test it routs and it is removed from play.
You order a unit to charge but then it has to pass a wanting to charge test and if it passes it then the target unit must pass a received charge test, so sometimes charging units do not make contact and some other things may happen. Something similar happens to shooting, as targets must pass a received fire test.
RRtK is a ruleset to play big battles and it is completely different to any other rulesets covering the same thing. If you like THW reaction system you'll like RRtK.
Personally, I think RRtK is unbeatable in solo playing (and there is a nice campaign system to play with), but also there are other rulesets like DBA or Warmaster that could be better for head to head playing.