I do believe that ProphetSword did mean an events driven battle, I just wanted to point out that we could do it otherwise in DC.
I don't know if we can change the small pic...I suspect not, though. The wall trick and icon change trick were mentioned by CocoaSpud, but not explained. I do know that we can not change backdrops using the wall method. I assume that we can not change portraits using the icon method. But, as I know what 'assume' means, I will try it anyway/
The random encounters are often referred to as 'wandering monsters' in the GoldBox parlance. Sorry to get your hopes up.
I guess the term comes from "...a monster wanders up to your party. What do you do?" The encounters in the GoldBox games often used sprites that would approach based upon decisions. I just don't have any sprites for the monsters I'm using.
The more complex notion of wnadering monsters is a great one, though. It's just not right for this design. Plus, this is the one that I'm trying to only use artwork that you (Dinonykos) and Uatu created.
I've actually come pretty close to succeeding on this bit with the art. All icons and walls are by you two. But, I think most of the backdrops are mine and about a third of the small pics/portraits come from Ziroc and goldBox sources which I've touched up.
Oh, I almost forgot, you are correct in the percentages I assigned. It's 1 divided by the total options left including that one.
Something my graphic doesn't show, is that you can have multiple chains run off of one utility or an utility and chain events.