Edit (Sigmar 02-Jan-2010): Things in the Warhammer Fantasy Battle world have changed quite dramatically since this post (8th edition rules have been released for starters !) Since the latest rule update, Skaven are still rated highly but are not ranked as well as High Elves or The Empire (Wood Elves and Bretonnians are now the weakest armies).
To check out the most recent poll:- The Best and Worst Fantasy Battle Armies for 8th edition.
Tournament results vary a bit year on year but Skaven always do well.
If not the best, they are usually in the top 3 or 4.
But why ?!
I have been banging my head against a wall trying to work this one out.
Traditionally, I used to always be of the opinion that toughness was the most important single attribute in the game (maybe because I always fought Dwarfs and was looking for an excuse !). This has changed over time due to the ubiquitous distribution of great weapons but toughness still remains one of the keys to victory for many armies.
So what else tops the list ?
Well, I would have thought leadership would be right near the top in importance. Surely it must be ! It's what holds your whole army together.
It seems I must be way off the mark because Skaven are weak in both of these departments.
So what makes Skaven so good ? There's a common theme throughout the Skaven army and it's cheap fast moving troops which provide a dispensable source or rank and file bonus.
There are 2 special Skaven Rules that further enhance the importance oof cheap rank & file Skaven clan rats and other units :-
1) Strength in numbers and
2) Life is cheap.
(see my earlier Skaven special rules post for details)
They key to victory against an enemy of rats will not be a line of cheese baited mouse traps, trust me, it probably won't work. The key is the black mamba circle and strike (you have to flank the ratties and take their precious rank bonus - which they can use to fortify their leadership value for ALL tests).
Use cavalry, flyers, magic and whatever else you can think of to get at their tails.
Hmmm... I will be giving this a lot more thought and coming back with some specific tactics.