Most gamers like to make up their own rules, to invent characters, and perhaps even design their own scenarios. Traditionally, when players re-interpret or modify the game rules, or add new rules of their own, these are referred to as house rules' - literally the rules played when gaming at that person's house. When you go round to a fellow enthusiast's home it is only fair to play to his house rules. After all, he is supplying the tea and biccies.
Warhammer lends itself to adaption very well and players should feel free to change, remove, or add to the rules if they wish. For example, why not stage an attack on a Dwarf miners' mule train - you'd have to make up rules for mules and wagons, possibly allowing time for loading up the train with gold, and decide how the loss of their gold affects the miners. As is well known "gold fever' can have very profound effects on Dwarfs and turn them into unstoppable maniacs! Obviously it's possible to imagine many ways of representing such a scenario, or any situation, from a raid into underground catacombs to sieges, street riots, bank robberies and bar room brawls.
I know of experienced and very confident players who go even further, changing some of the basic rules themselves to suit their own style of play. And why not indeed! Warhammer is supposed to be a broad set of game rules that hardened veterans can adapt, change or add to as they please. The only disadvantage of making up your own house rules is that you will have to revert to the normal rules when playing other gamers, or if you're taking part in a formal competition where a common standard is required.