The full rules as well as extra info can be viewed on the OrcFace website.

Welcome to DreamDisc '24!
DreamDisc is the premiere game jam for Dreamcast developers,
with the goal of bringing the community together and putting out some new
homebrew games for dedicated Dreamcast fans to play.

The submission period will be Dec 20th - Jan 3rd. Community voting will be taking place in the Simulant discord server, and separately a panel of judges will be voting on their favorite games.
 Space permitting, the top 10 games  from the judges panel will be put onto a gamejam disc, and the top 3 games will receive a cash reward (more info on the website)

A shortened list of rules will be provided below, although I heavily encourage checking out the OrcFace website if you're interested in voting or having your game on the DreamDisc.

Rules:
1. No fangames/nsfw
2. Only use tools you can legally use
(KOS, Simulant, AntiRuins, Raylib4DC are some good starting points)
3. You can submit games you've worked on outside of the submission period
4. No AI generated content unless unless you have been granted the right to use the training data by the IP holders (Like Adobe Photoshop)
5. Any team size is allowed

You are free to submit tools related to Dreamcast, games and tools on Dreamcast, VMU games and related tools, as well as hardware. 
Read the website for more info on submitting hardware.

If you want to chat with other participants, get help, or participate in the community voting, please join the Simulant Discord