Preempting Magnus here, we came upon the idea that establishing a few ideas for adventures in Yume-Do would be cool, so PCs can do dream quests or fight nightmares within dreamer's minds.
The Shadowlands book established how to go about that:
1) Establish rules that work only in Yume-Do
2) Offer Opportunity Uses within Yume-Do.
Central to Dreamland should probably be dream-logic: Stuff just happens or just changes all the time. Consequences are not as pre-determined: Falling off a roof often just shows you that you can fly.
Also, wanting something goes a long way towards getting something.
Ideas include:
- you can spend Opportunities to change any environment you are in.
- any Condition can be ended with a check to think it away
- it may be possible to think away opponents weapons (or think swords into wooden swords), as it is possible to think new weapons into existence
- one could think about making importuning invocations easier in Yume-Do (and availanle to non-shugenja, as dreaming to have magical powers is common). That has the advantage of limiting what PCs can do to already established options.