I have been thinking about game design a bit recently, triggered by the comments about realism vs abstraction. All game systems are inherently compromises between realism vs abstraction, complexity vs simplicity or rules ligth vs rules heavy.
I have seen a lot of articles that imply that simple rules and rules light go had in hand whereas the reality has in my experience been the opposite. If you have a very simple rule for each situation then you can easily end up with tens of hundreds of simple rules, one for just about every situation. AD&D is a prime example of this with just about everything being handled in its own unique way.