3rd Edition is published by Siege Works Studios, 2nd ed in the late 80's early 90's was published by our good mate Chris at Outland Games, just to clear up the confusion. :)
You can purchase a PDF copy of the rules at the website as well as loads of free PDF's and also army lists supplements including exciting additions like Portuguese.
Although I had been playing Koenig Krieg personally since the early 90's using 2nd ed when I had the chance to buy the rules and redo them I jumped at the opportunity. The earlier editions were written for the experienced Koenig Krieg gamer who already had 10-20 years gaming experience with the rules, but was not very user friendly for the newbie. When I took over the ownership, I reformatted and clarified the rules so that not only the veteran die hard Koenig Krieg gamer's but also new players could enjoy the experience :)
What are the differences between 2nd and 3rd. Well really all 3rd has done is amplify the rules, so that they are clear. Loads of examples and diagrams are in the rules, it is full colour as opposed to earlier black and white, it actually has a points system that works as opposed to one that does not, which is why all the gentlemen that still play 2nd edition have never bothered at all with playing points (quite right too as the the old points system was decidedly in favour of Prussians) and instead happily match armies up against each for a gentleman's bash. Which is not a bad way to play a game, especially with a bit of port and lively conversation amongst friends, which is why I salute them and say good show in my most dignified 18th century manner :)
3rd has also introduced the ability to play Koenig Krieg tournaments of which we have had a few wonderful comps over the years in Australia and Italy to name a few of the places comps have been played.
The army lists which are points driven are in fact far more historical in the organisations than in previous editions and really lends it self to good old historical gaming without having to be an 18th century scholar and military historian. I did all the hours of pouring over historical orders of battle for each nation so that you did not necessarily have too :) If you are not a points gamer and enjoy realistic historical orders of battle just follow the army organisations in 3rd ed and ignore the points :)
3rd is also well supported, with loads of free PDF supplements as well as 12 PDF parade handbooks covering the Holy Roman Empire, Russia, Prussia, Britain and her allies,Austria, Spain, Sweden, Portugal and Turkey. There are proto lists for Persia, Durrani Afghans, Mysore, Mahrattas, Mughal, British East India, FIW to name but a few of the releases to come.
We also have started a small range of 15mm SYW which in time will expand as well as just having purchased a range of 28mm SYW Hanoverians and Hessians for our imagi-nations and small actions games to be released later this year. Here is a Hanoverian Mtd Officer beautifully painted by Chokidar from our new 28mm range.
In short, 3rd ed is a streamlined and more modern and easy on the eyes edition which crisply and clearly allows players to enjoy the wonderful world of 18th century gaming without having to spend half the time filling in the many blanks and presumptions of the earlier editions. It is as much for the beginner as it is for the veteran Koenig Krieger.
Hope this helps :)