Lucid worlds can be entirely independent or connected to other lucid worlds. If they're connected, what you do in one of the lucid worlds might affect the other one. You can go from one to another, bring things from one world to the other and so on. For that to be so, there needs to be a 'bridge' that connects them, a small lucid world entirely made to work as a way to connect a world to another. These bridges aren't usually created automatically like common lucid worlds, you have to work on them by meditating before sleeping, or in-dream. If you're having a lucid dream inside a lucid world, you can begin to think you're leaving the place to another lucid world, you can close your eyes and imagine you're walking through a place that would be the bridge and when you open them again, you're supposed to be in the next lucid world (please don't just randomly walk thinking to go to another place, you have to have a lucid world in mind to get out of the current one) if you wish to make a bridge outside a dream (irl), you'd have to, before sleeping, visualize your dream worlds. Think that they have a bridge (small world) that connects them, it's not necessary to visualize the bridge as a literal bridge, after all, it's also a dream world. It just needs to be connected to other 2. If you do this and claim there to be a bridge between worlds, it will start appearing slowly until it is there. It's quite simple. Sometimes, these bridges can be 'blackouts' inside the dreams. When you're having a lucid dream and it suddenly ends and then you're in another lucid dream, well, that's pretty much how a not finished bridge works, simply ending a dream for you and starting another one. (Don't mistake them with common dreams outside lucid worlds, these blackout only happen when you want them to) Unfinished bridges aren't visible, you just go from a world to another. Unfinished bridges can be dangerous though, you might wake up while using them. Try to finish a bridge before using it. A finished bridge is visible, you can even interact with the world, even if its small. Bridges can be anything you want, but it must have something you can walk on from a place to another. My bridge is a field - it has tall grass, and you can see the city far away (that city is the city of Twisted World https://drawn.digifi.ca/play/f5rx8n ) and a city on the other side, which already looks very different from the one of Twisted World (different colors and all). To go from one another I walk through a small road that you can find next to the field. I named this bridge dream fields :) What's an advantage of bridges? Well, you can scape nightmares easily. if you've done something that triggered a world (such as saying that you know you're dreaming, something you SHOULDN'T do unless you're an advanced oneironaut) you can go to the next lucid world to avoid waking up or having a nightmare. If you're simply bored of a dream, you can leave it without waking up. It can also help you maintain over a lucid world without visiting it often. When connected, if you interact with one world, it already counts as if you've interacted with the other world that is connected to it.