The only real rules that dictate raids are the 7 minute NLR rule and a loose 'don't mug people constantly' rule. What should be added is a 10-15 minute rule between raiding people's bases so you cannot just hop out of NLR to constantly attack someone's base without repercussions. It also lowers the chance of people being complete arses and raiding you as soon at the timer finishes and gives the defenders more time if its a repeat offender.
