"Add a battle"
Quick tutorial.
(I wrote them up for most of creating a mission - search, 1 year, my name, terms +tutorial -"re: " in Player Guides.)
Certain maps will also cause this behavior spontaneously if they contain two different factions, one set to "enemy" and another set to "rogue" or even "friendly," though the latter won't attack players. Actually getting to see such a battle, however, depends on whether the two groups spawn within each others' aggro ranges, so it isn't a guarantee.
If you want to be sure of seeing enemies fight, use "add a battle." You can also have a friendly or rogue ambush trigger during a boss fight goal; create an "ambush" goal and set it to activate when the boss reaches a certain level of health.
"Bombarding the CoH/V fora with verbosity since January, 2006"
Djinniman, level 50 inv/fire tanker, on Victory
-and 40 others on various servers
A CoH Comic: Kid Eros in "One Light"
Great help! Thanks. And Memphis_Bill, I did your first couple of tutorials. They are amazing and really helped me get my first arc done and published.
I was playing a Dev's Choice arc (It was hilarious.) and noticed in one of the mission that two different baddie factions were fighting among themselves. I would like to have something like that in an arc I'm working on. So... how do I do that?