House rules
During my games of Necro, I tend to keep things like house rules to a minimum, as I find it can bias a game far too easily, saying that, I still have a few!
Conveyor belts. I have a few of these in my scenery, and tend to use them as a sort-of walkway. But, to represent the fact it's a conveyor belt, I figure it should have a belt movement stat.
So, roll a D6, 1, 2, 3, it moves one direction, 4, 5, or 6, it moves the other. I tend to have mine on a fixed speed of 2" / turn, but feel free to roll a dice, or make up another way to set the speed.
Environmental damage. During a game, I've found no matter how well you plan, something always gets knocked, or falls etc... I play the rule this represents actual damage. A walkway falls onto your miniatures,. S8 hits for them all. They accidentally fall off a building, falling rule applies etc... It tends to make people be far more careful!
Scatter, I play the rule scatter has to move to the front of the model, as I've seen people do other various things.... I also play the rule of "realistic" scatter. Your grenade scatters into a building with a few inches scatter left, it bounces back!