I am searching for ideas.

Say the campaign setting is not a region set on a planet, but a demi-plane in itelf. So, when you reach the map's borders you don't have other regions waiting for being described, but the end of the demi-plane. Tell me about your ideas of the demi-plane's borders.

1) Ice Wall: Inspired by a Game of Thrones. North is a great ice wall protecting from the cold and eternal winter beyond. If you go beyond the wall there is nothing living, and soon it's eternal darkness and intolerably cold.

2) Land of the Dead: Progressively the world appears dead and rotting, with lurking undead. Then it's mist land with more undead. Then if you try to go deeper into the mist, your life begins to drip away (i.e. natural energy draining) and you eventually become an undead.
Note: people may have shrines and temples to the dead in these border regions where they can meet with the spirits of their dead relatives.

3) Border Ethereal Plane: In the land you need magic to reach the overlapping ethereal plane, but moving to the land's borders you eventually walk into it.

4) Plane of Shadow: As #3 but Plane of Shadow instead of Ethereal.

5) Chaos: As in some Elric novel, you reach ancient lands under control of the gods of Chaos.

By demi-plane I assume you mean a pocket dimention?

Depends on the setup.

Some thoughts.

1: After a point creatures feel compelled to turn back. This compulsion gets stronger as they move forward till it overwhelms. They may not even be aware that they turned away at first. Or it may be a growing urge they are aware of. *Metamorphosis Alpha*

2: Space. The literal edge of the world.

3: Wrap-around. Go far enough east and you eventually are approaching your start point from the west. Going up too high hits a solid barrier. (The rock of the bottom of the world?) *Original Land of the Lost*

4: Increasingly pristine forests. Too pure in fact. Staying in these regions is harmful to non-native flora and fauna. As if "wilderness" were a radiation. *Dragon Storm*

5: Ever increasing levels of "reality". Magic begins to fail, then fails outright, fantastical races will lose all non-natural powers and may start to revert to their baseline. The zone may be covered in ruins of some past civilization. Or may be a modern city pristine and deserted as if the people left recently. Or they may walk into the real world. *Xanth*

6: A stark white plain extending out as far as anyone has dared to go. Or the plain may be gridded in enormous hexagons that are not immediately apparent due to being so large.

Quote from: Turanil;896514I am searching for ideas.

Say the campaign setting is not a region set on a planet, but a demi-plane in itelf. So, when you reach the map's borders you don't have other regions waiting for being described, but the end of the demi-plane. Tell me about your ideas of the demi-plane's borders.

- Minecraft Far Lands: Reality becomes twisted and things cease to behave in predictable way until everything becomes too abstract to comprehend.
- Time slows until it ceases to progress. You become trapped for eternity without understanding it. If somebody pulls you back 1 million years later, you wouldn't know that you were "gone".
- Loop. You arrive at the other side of the map.

If you want, you might use my world generator - especially "BORDERS" section.

Quote from: Omega;896519By demi-plane I assume you mean a pocket dimension?

Yes, "pocket dimension" seems a much better term.

Already good suggestions on both posts. Thanks!

An immigration checkpoint.  (ducks)

And another.

The further you travel out the more primitive life gets with no signs of people. Just flora and fauna. The age of great beasts, mastadons and sabertooths. Then dinosaurs, then reptiles, then amphibians, then fish and insects and so on. *Cesta do pravěku, (Trip into prehistory)*

There is none. You just get back to the start point, forgetting you ever left for the trip.

Everything starts getting increasingly pixellated... lower and lower resolution till it's just a grey-brown haze.

Similarly, Lego... it's all made of Lego.

Quote from: Turanil;896514I am searching for ideas.

Say the campaign setting is not a region set on a planet, but a demi-plane in itelf. So, when you reach the map's borders you don't have other regions waiting for being described, but the end of the demi-plane. Tell me about your ideas of the demi-plane's borders.

1) Ice Wall: Inspired by a Game of Thrones. North is a great ice wall protecting from the cold and eternal winter beyond. If you go beyond the wall there is nothing living, and soon it's eternal darkness and intolerably cold.

2) Land of the Dead: Progressively the world appears dead and rotting, with lurking undead. Then it's mist land with more undead. Then if you try to go deeper into the mist, your life begins to drip away (i.e. natural energy draining) and you eventually become an undead.
Note: people may have shrines and temples to the dead in these border regions where they can meet with the spirits of their dead relatives.

3) Border Ethereal Plane: In the land you need magic to reach the overlapping ethereal plane, but moving to the land's borders you eventually walk into it.

4) Plane of Shadow: As #3 but Plane of Shadow instead of Ethereal.

5) Chaos: As in some Elric novel, you reach ancient lands under control of the gods of Chaos.

All 5, depending on the character's frame of mind or belief systems, the reality is that they have reached the end of the simulation, and it is just looping back on itself. Otherwise, taking the right path, you can reach the end of the map, Land's End, beyond which is a gas torus, where matter flowing over the edge recycles itself underneath. Somewhere beyond are the makers, maybe biological, maybe an Alien AI, and their doing is somewhat non-understandable from a human's limited perception. Thus better to retreat to a place like the land of chaos, which can be made sense of.

Quote from: Turanil;896514Say the campaign setting is not a region set on a planet, but a demi-plane in itelf. So, when you reach the map's borders you don't have other regions waiting for being described, but the end of the demi-plane. Tell me about your ideas of the demi-plane's borders.

If you just want to end the game world and not have the players go any further in that direction, then you can use any sort of clearly impassable terrain to block them: ice wall, mountains as at the edges of Ringworld, a terrifying abyss (great for throwing unwanted Coke bottles into), a wall of unbreakable glass through which is occasionally visible the tacky gift shop where the snow globe sits on a shelf. If these are obvious throughout the demi-plane, that can create a sense of claustrophobia (for good or bad); if they are slowly moving closer, that can add a sense of urgency.

If you want to discourage travel away from the demi-plane but leave open the possibility that there may be something they want to visit out there, then you can use any sort of sprawling and featureless terrain: trackless desert, rolling ocean, frozen waste, and so on. (If they can fly long distances I suppose the abyss goes here.) So they may eventually find directions to some nearby sub-demi-plane, an island or oasis at a manageable distance but nearly impossible to find by random exploration. If the players are stubborn enough and have the means to waste a lot of time exploring it to ever increasing distances, or if the terrain turns out to contain resources that the players would like to harvest, you can add difficulty in survival, in the form of endless storms, the life-draining property of the Land of the Dead, or utterly inhospitable climate. Populating with tough monsters might just be viewed as a challenge by the players, especially if they can gain XP or treasure.

You can also have everything loop around, so that any attempt to leave brings them back into the demi-plane (either reflecting back to the point they left from, or wrapping around to a point at the opposite side, or to some unexpected place (e.g., always wandering out of the mist into the courtyard of the inn at the center of the demi-plane). I like the idea of a wasteland where traveling a significant but not impossible distance in any direction leads you to the same demi-plane, but with slightly altered history (even extending to the actions of the player characters in previous sessions).

I also like the idea of a sprawling mud flat in which lost things from anywhere can be found, peopled by scavengers who traveled there to find something precious they lost and who have slowly descended into insanity. But the players may spend too much time trying to find things or make use of this place. Maybe the borderland could be a vast realm of illusion, where those who wander in spend long periods in pleasant dream worlds, either dying there or waking up as if from a coma when the border shifts by chance.

Most of my ideas are based around keeping the game focused on the demi-plane rather than whatever is beyond its borders. Is that your objective?

The game should of course remain focused on the land that was designed. But I like the idea of having the borders be an integral part of the setting. So far I like these ideas (but I am interested to hear any other idea I may not have thought of) and need to find a way to articulate them:

1) Common people and animals naturally shun the borders. It takes a Charisma save (or vs. Spells) to go through and beyond.

2) The dead are said to wander beyond the world's borders. There are some shrines and chapels dedicated to the ancestors' spirits and to the deities of the dead near the borders. (Different faiths may coexist, evil and neutral ones.) People may come there to make offerings and hope to get advice from their ancestors. Sometimes the spirits of the dead might come and visit them. Some are benevolent, but others are evil; the evil one would be shadows.

3) Beyond the borders the land becomes more and more like a world of shadows (i.e. the Plane of Shadow) until it becomes a featureless and misty gloom. But between the normal world and this gloom, there is an area like the Plane of Shadow. Its size is fluctuating, maybe 10-40 miles.

4) As inspired by Moorcock's novels, the world's size could shrink or expand. A champion of Law, great priest with an important number of followers, powerful sorcerer, etc., might create new lands (a domain), thus pushing the borders ahead. Some high level PCs should be able to do this and get their own domain out of nothingness. The borders / land of shadows is now beyond their domain, where formerly existed nothing.

5) When evil grows in the land, the borders may recede, which first begins with creatures of shadow invading from the borders (e.g. undead shadows, shadow mastiffs, etc.). Note that shadow creatures would be spirits that try to incarnate in the material world, beginning as shadows before eventually becoming living monsters.
Note: Rangers in such a setting would not be dedicated to hunting evil humanoids (ogres, trolls, etc.) but their abilities would target creatures of shadow. Rangers would mostly operate near the borders.

And some more.

6: The past the edge the world is faded, greyscaling out and eventually just vanishes. There are remnants of cities and wilderness out there mostly abandoned, but places to find supplies or even magic/tech that is in demand. Some sections will need to be bridged  somehow to get to and theres the risk that the patch you are on may vanish. And you too. *Fade (a game I was playtester for a year ago)*

7: Past the demarcation is a world of wilderness, horrific monsters, and silence. The monsters were once people and animals. And fighting them can risk becoming one too. Lots of ruins to explore out there though. *Stand Still, Stay Silent*

Well, possibly hazy pathways to other demiplanes or planes, but in a dangerous environment where only the very skilled will be able to know where to go.

And another.

You get to the edge and see a giant disembodied hand painting more landscape into existence.

There's nothing save a dark void that sucks the very sanity from the soul of whoever's unfortunate to stare at it, and a thin, barely visible and ever shifting bridge made from prismatic light, that seems to lead only further into the void.