My friends and I have regular LAN parties. Back in the day these were real LAN-only games without any connectivity to the Internet, matchmaking or progression systems. People occasionally played team-games but the real measure of a man at the LAN was in Free-For-All.
Every man for himself, the true test of skill! (Actually a test of stamina over 4+ hour games).
One man standing atop the conquered nations of his peers while earning their grudging respect! (Actually while they all seethed and grumbled about cheap tactics and underhand ‘diplomacy’).
One of the key tenets of playing these FFA games was the necessity of Casus Belli.
Casus Belli is a justification for war. In the past when governments were tied up strongly with religion it was important for foreign policy to get around those annoying “don’t kill people” clauses in religious texts.
Ie;
“We had to invade that area because the poor people living there were being oppressed for their religion!”
But isn’t that area swimming in gold-rich lodes of ore?
“Yes, but that’s purely a coincidence.”
And after you invaded didn’t you execute all the religious dissenters?
“Yes but they were heathens.”
While fractionally less serious in the LAN Gaming world Casus Belli was required for similar reasons.
Our Free-For-All games all had a similar rhythm; everyone would turtle for resources, build up an uber-death-army then attack. The tricky bit however was not getting nobbled by someone else when you were away on your Grand Crusade. If two players were fighting then it was a great time for a 3rd to go and trash the attacking player’s base.
Hence our games often degenerated into this;
Also there was some psychology involved; if you saw a player go out and attack someone else then you knew they were feeling frisky and you were likely to be next.
The best way around this was always to play the aggrieved victim of attacks. You weren’t stomping someone else’s base for the hell of it; you were desperately defending against unprovoked aggression. You were the plucky defender stoically hanging on by their fingertips. You weren’t violently squashing your neighbours and stealing their resources; you were just defending yourself.
Honest!
Of course, as time went on the threshold for war reduced; going from “he was attacking my capital city” to “his choice of architecture offended my sensibilities”
As the games went on resources became the deciding factor in a lot of engagements; we literally strip-mined and de-forested the entire map. This meant wars could break out over a small patch of scrub-land or a large stone.
So this means this guy was often the ultimate instigator of conflict;In Warcraft 3, once you set a worker on his task he’d happily make his own way to harvest the resources he needed. This lead to the scenario where someone’s worker marched out of their base and into mine. There he blatantly, BLATANTLY started chopping one of MY trees.
Well.

I was clearly obligated to trash the offenders base with extreme prejudice.
Oh and mine all the resources of course…