The act of leaving everything you know behind in order to face chaos, death and blood carves a space out of the world, A seed that sprouts slowly and subtly but grows more concrete as adventures are scarred and beaten in the ruins, tombs and towers where they gain their gold and experience. This magic starts as something subtle, barely remembered dreams, shapes of adventures to come. Time and survival carve out a piece of dream-space where future delves can be planned and past adventures can be memorialized in a room-sized pocket dimensional demi-plane: the Tavern Between Dreams.
During those first levels, they have vague dreams of symbols that represent the modules that could come next, perhaps if there is more than one to choose from, you allow them to choose a vague symbol representing an adventure to come. The dreams become more clear, more lucid over time. There is a table for the group to sit around, a tome to write down their intentions when they wish to break the laws of creation (DCCRPG, 306).
Eventually, someone is there, a castellan, a servant, sometimes referred to as a tavern-keeper. The Tavern-Keeper serves drinks and offers an understanding ear. Whether the Tavern-Keeper is a soulless construct, a ghost or some kind of gestalt soul of all of the adventurers who died on the way is unknown.
1st: Experiences in the space are vague and misty, INT check DC 10 to see if you remember anything but a single symbol or image upon waking.
2nd: It is all a faraway dream but growing more tangible while you are there, INT check DC 5 to see if you remember anything more than a single image or symbol upon waking.
3rd: A vivid and clear waking dream, the table and the tome with its quill are solid, you remember everything upon waking.
4th: The tavern-keeper is present, acting as if it was always there.
5th: Grottos for trophies and memorial statues representing those who have died are present. All trophies are dream-objects representing great deeds. Scrolls recording the band’s adventures are present. Real world items that were being held while falling asleep can be stored here.
6th: Party members can invite an ally to join them here for a lucid dream. Oaths made here are unusually binding.
7th: Friends and loved ones can offer a token while in the Tavern Between Dreams, this token can be used to contact them through dreams.
8th: Messengers arrive who can send and receive missives to mortals through dreams.
9th: The messengers within the tavern-space can petition greater powers (demons, devils, elemental lords, beast lords, archmages, liches, etc.).
10th: The Tavern Between Dreams anchors itself into the waking world, becoming a pocket plane with a door that can open whenever 3 or more members of the band are within sight of one another.
Essentially, this whole thing is a corny reason to deposit the group from one DCC module to another with a thin in-game magical excuse, giving the group an arcane place that grows with their characters in which they can celebrate their victories and raise their cups to the victorious dead.