Yep, no rules on invasions.
Which is exactly why I feel absolutely no guilt about using the cheapest, grimiest, most asshole methods imaginable to screw invaders who come into MY fucking world and try to kill me. Tranquil Walk of Peace spam, backstabs from summoned players while you try and attack me, summoning three people and triple teaming you, 1-2 hit kills with OP weapons you shouldn't have at the time like Gravelord Sword, all of it.
And then the ganking douchebags wanna cry and send ragemail when you do it. And it's like "Fuck you invader, you came into my world while I was minding my own business and tried to kill me." They deserve no sympathy and no honorable fights. Kill their asses and continue on your way.