Well my thinking is this: there is no comparison between a normal human and a Space Marine, except maybe if the human is carrying a plasma weapon or something. It's a totally unequal fight. So it doesn't make sense for a tournament that includes Space Marines and regular Imperial citizens. And overseeing regular human tournaments is only something I could picture the Ultramarines doing. Astartes tend to have nothing but contempt for the fighting capabilities of an unaltered human.
That option means you invite them to attend the Tournament and watch it, making it a public affair rather than a private one. Then you can up the ante further by allowing other Chapters to compete. I get where it could be unclear.
Just a weird barbarous tradition of the chapter to hold lethal combats?
That's what I was thinking. A more bloody version of the tournament.
Ah, that's probably why ideas don't really come to me for it as quickly, it's pretty uncommon for Space Marine chapters to organize deadly combats among themselves. Matters of honor, personal rivalries and such aside, killing each other for sport is uh...definitely against the Codex Astartes. That level of wastefulness and callousness does seem better reserved for Chaos. I dunno though, maybe Space Wolves do some shit like that.
At any rate,
Deathmatch (Imperial)
1. Chapter only
2. Allow Spectators
3. Allow Other Competitors
I thought about adding, like, captured Xenos to the competitors or something, but that also seems pretty far-fetched for Imperial Space Marines. This one would be different from the standard tournament in that, the limitation on other competitors is anyone who feels like getting chopped up by a space marine. That and you might end up killing someone outside the chapter and piss some powerful people off.
editYou know, this might be a good opportunity to dig into Chapter histories. This goes back a long time to stuff we talked about, incorporating more narrative that relates to the founding chapters and some of the successor chapters. If you've got some system where you can swap events in and out based on a parameter like what chapter is being played, you could incorporate a lot more specific things. For example, Blood Angels recruit from Baal, where the aspirants have to cross a rad desert filled with giant rad scorpions and pockets of deadly radiation and all this shit. If they make it to Angel Falls they perform the trials and stuff under the watchful eye of some Blood Angels, who pick the winners and take them up to become initiates.
So I kinda picture something like:
Recruiting Ceremony on Baal
[Text blurb]
1. Oversee The Trials As Chapter Master. (Grants x initiates immediately, grants some planetary rep if you don't already have max. Baalites do love their Blood Angels.)
2. Petition The People (Grants x+y initiates immediately, but reduces planetary population by z%.)
3. Accept Only The Best Of The Best (After totaling the maximum # of initiates granted, reduce that number by 50%, and grant the remaining initiates bonus training experience.)
This is an example of something to do later to flesh out specific chapter features, to give them more flavor. Maybe the kind of thing you can offload or outsource to a degree, as there are lots of chapters with pretty arcane histories.