In 2011 I discussed a crystal called "celvenate" which contains "magic stuff" required for teleportation. The eventual goal being that anything related to teleportation would cost the user some amount of this material (word of recall, TP to a specific location spell, TP'ing across fragments of the Shattered Planes via the Random Dungeon system).

As far as applying the stone goes, perhaps an option is that applying it returns you to a specific place (savebed) but it can be redirected by certain methods (location-specific spells, or a crystal made beforehand with specific coordinates tethered to it).

Rest mode locking is a very good idea IMO, and is extremely easy to implement.

As far as invoking/summoning goes, I can't think of any specific examples right now (very tired) but certainly worth exploring.

Original topic: https://www.daimonin.org/10769/teleportation-concept-proposals/

Just want to say I am an advocate for this return to town teleport thing, and 100% support the resting first so you cant just teleport while fighting.

Another thing I have seen is teleport stones on different spots on the world map...like 1 east, west, north, south etc. to help with navigation.

I've not looked too closely at the code but I would imagine that a lot of the code for a theoretical homestone would be very similar to the code used to jail a player with the only difference being that the target location is the player's apt/savebed point rather than jail along with the activation being with an item instead of a DMBuster /talk command from a vol etc.

Just as an additional thought normally using or applying an item disrupts resting so would that have an impact on the homestone since potentially applying the item would stop you resting and then when it checks if you're resting you would fail that check

One other thought I've had is that using a homestone could break other scripts. For example I remember in Tetranesia that there was a script that called over a giant to push a raft and if a player logged out the giant lost it's target and scripted ended up hanging/crashing. Using a homestone would have a similar effect. You also have things like the Haunted Mansion quest where players could in theory escape a scripted death. I'm not too sure how the plane script would work if you use a homestone mid flight.

Having said that I don't think it's disastrous as players wouldn't be stuck and presumably if they break scripts they can report it and then scripts can get fixed. I think main class of scripts affected are ones that rely on the player to go to a certain location (e.g. shop and shop portal)

As far as the things raised in the reply

1. I think nothing catastrophic would occur in the Tetranesia quests and as you said a lot of it can be replicated by a person dying etc. If any scripts do crash then it simply means that the function ceases rather than a server wide crash. I think for the airplane most of the data is kept on the ticket object rather than invisible quest data so I think discarding the ticket would reset the player. Having said that it's an untested hypothesis. I would expect that if a homestone does break any scripts resulting in a player getting stuck then a homestone also allows the player to escape so it would probably solve most of the problems it causes.

2. In the shop basically way I think it is meant to work is that any unpaid for items cannot be used (although recently I think arrows could be used due to a bug). If you enter a shop with unpaid for items the next time you leave it will try to pay for them with normal logic. Only slight exception is Apple Orchard shop that I believe uses special tickets but if you manage to smuggle them out and go to a regular shop it charges it's negligible examine value instead of apple orchard currency.

3. I had considered homestone prevention areas but the problem is that any script that can be broken by a homestone is also an area where players are most likely to get stuck. For example in the shop if a player has an unpaid for item that they can't find and not enough money to pay for it they'll be stuck for a long time.

Also note that I'm not opposed to a homestone in principle. Just from a QoL perspective I imagine if a player is in the Lom room and needs to return to sell loot then a homestone is a lot more appealing than a mad dash through GT where you risk death. I also think it's unlikely to cause any major bugs unless players go out of their way to do so and similar effects can be achieved by dying or logging out.

I'll also add that apartment portal leads to the last place you entered apartment from. This means that if for example you're stuck in Tetranesia and entered your apartment from Tetranesia last then the next time you leave you'll return to Tetranesia. This means that in theory an evil mapmaker you teleport you to a 2x1 room with other tile being a portal to your apartment and if you enter it not even a homestone will save you although I doubt that will ever exist!

Sitting down there in guildhall ant cellar and apply this homestone, suddenly teleported back to tavern, this felt so good. Can't wait to do the same deep in dungeons. Code must be tested, if it works also with saved beds.

Easiest way to test this, is to put an artifact with type 160 in artifact list. I grapped my creditcard artifact and made it temporary type 160. Finally we need to think about, what grafic we use for a homestone and how expensive a homestone should be. I personally would make it not to expensive. Don't want player to think: "But with my current level tabernackle express is cheaper!" I would go for max 1 gold or perhaps cheaper.

I have updated the above code. 

This is my next goal. I will look in shop exit logic and in drop item logic. Shop exit logic i will try to go in the loop, where all unpaid items are paid. Must be easy to change it to drop all unpaid loot and allow teleport out of shop. This will end the era of new players stucked in shops.

I also want to look in drop logic, it player drops unpaid item on a non shop tile, this should deleted the item too. If you say there was something in past, perhaps i find this old code.

Allowing a prayer instead of a homestone, could also lead to stucking situations, if player is to low to learn it. But if we have a stucked player somewhere, with a homestone we have also the option another player comes in there and bring a homestone to the stucked player. Homestone should not be the main fix for stucked players, it could be a help as a side effect of this logic. I personaly would also target mages for things like teleporting to towns. Could be easy to build in a logic, where mages can reach from everyplaces the waypoints by spells later. Of course for high level mages. I was also thinking to build a gm command targeting all waypoints and allowing to delete broken ones. So that would be same logic for a kind of waypoint spell for mages. Of course this spell must have a kind of channeling time, could be done first also with the player restmode. Mages waypoint spell i think should be only for very high mages (level 110)?