Looks like your message was cut off, but your description will need to fit within the short and/or long descriptions. You should be able to express the core nature of how the events are different in the short description and then put your legal language in the long description, perhaps with more detail on the nature of the event.
If you're ultimately looking for legal protection, you can't ultimately rely on just the event description, either. You'll need to get active consent from the participants, and likely use waivers for them to sign. You'll likely want to plan to distribute those on site at the event, but you can also include a link to them in the message to registered players, to try to get some of them signed before the event begins.
Either way, it sounds complex enough that you will want to email [email protected] to confirm the full details of your event.
Senior Event & Program Manager
Gen Con LLC