caravan: You are the last people from an ancient tribe. Now you need to find a new home. The way across the desert is hard and long to preserve your tribe you have to teach your knowledge to your children and them to teach it to theirs. You have to take care, that your people can get enought food and can defend themselves from the dangers of the desert. Until you reach your now home some day. Play an entire caravan and link people to others to pass on knowledge.
community caravan: There is the Desert. And you want to reach the other side. The artefacts found on failed caravans help you to survive. Until you become a failed caravan yourself a fresh set of carefully raised artefakts become available for other caravans. The longer the artifacts are „lost“ in the desert, the more powerful they get. So search the desert for helpful items of others that failed to help you now.
caravan messenger: you have to deliver a Message to the next city but you do not live long enough to do so. You neet to find an apprentice to to teach him the message before dying. You have say 3 slots of skills, but maybe you apprentice only has 2. pass on the knowledge wisely and choose the right skills on your path. Maybe you have to choose between skill and knowledge to pass on. Skills will help you reach the next city or oasis, but you will benefit from passed knowledge in the long term.
next step: find gameplay for the ideas.