A good criterion. I think that mistresses would make great ghosts too.

Re chao, there could be a chance for ghost to spawn from a specific death of a character. Also, levels could have a flag like "AllowGhostsToSpawnFromDeadChars = true" type of thing. There could be a cooldown timer between the time of creature death and the time when the ghost shows up.

Should the ghost show up on the level where they died? Or can they show up at any level where you happen to be? Should they show up where their corpse is?

You could offer a dead creature's corpse to a god to prevent the ghost from rising. (not every creature would have a soul, but say if you wanted to be sure that Sherarax didn't show up in ghost form...)

Ghosts could arise out of their former avatars being killed in a certain way (beheading?) or there could be simply a 10% chance of them showing up at all, after the death.

Another idea:
Engraving could be modified to require a tool, like a pen or something. Then you would dip the pen in some ink, and it would "engrave" onto the surface of the floor. Other ways to write would be by engraving with a tool that is harder than the floor on which is being engraved.

I introduce that idea because I thought it would be cool if ghosts could write threatening things in blood all over the dungeon floors.

People want ghosts to resemble those humanoids which they used to be.

For this, we will need to create a new way of making ghosts. This type of ghost will come from humanoids, and will be modeled on zombies from IVAN CVS, where special types of zombies were preconfigured using "CreateUndeadConfigurations".
Somehow, the torso and limb configurations will be retrieved to create a ghost and the colours of the torso, head and limbs will be switched to grey scale. One question is, what will ghosts equip? Does their gear need to be switched to ghost materials??
-One thing I'd like to implement is if the humanoid was killed by beheading, then the ghost that comes from that will forever wield its head (in both hands), and will also aquire an attribute bonus upon generation.
-Ghost bodyparts get sucked into hell when severed.
-Ghosts have move-type ethereal (walk through walls).
-After a number of days, all ghosts become invisible (as per another type of character we won't name)
-Ghosts of izzy, sherarax, danny?
-Ghosts of the slave from Attnam? If he dies during the game, he comes back a bit later to kick your arse. Makes you think twice about taking that guy with you.
-Ghost of Ivan??
-Ghosts only made from humanoids with souls?
-The question follows: Do goblins, orcs etc have souls?
-Undead dark frogs? (for that matter, zombie dark frogs?)

Most perversely there is the remote opportunity to make a spell scroll that splits the player's body and soul apart, so that the player becomes a zombie and must find his wandering ghost (somewhere on the level) in order to become human again.

What other things could be suggested to make ghosts more integral to the game?

I programmed a few humanoid characters to use wands in CLIVAN. If you come across a goblin warlock, he will zap you with one of Teleportation, door creation and acid rain (finally a use for wand of acid rain). He has all three in his inventory.

I don't know if it was totally crash-proof, I don't know what happens when an npc wand-user tries to zap with both arms severed.

Many more hedgehogs will need to be sacrificed before that happens!

Heh, have you considered developing IVAN at any point?

Thanks for spending time playing CLIVAN and spotting bugs

I don't know how widespread the shopkeep teleport bug is. My guess would be that it is limited to CLIVAN. I had hoped that most of the bugs were squashed, but I made quite a few recklessly implemented changes, so stability is not always guaranteed.

Just out of interest, what did you change the rookie dwarf's HP and Day Requirements to?

I'm glad you like the new creatures. Welcome, and be sure to stick around

Hear hear!

Continuing this thread. Performing a diff using WinMerge on Vasily's script.cpp with the one from IVAN CVS, reveals that the changes required to "burst" the script files involve less than fifteen lines of code:

In script.cpp:

...
    if (Word == "Include") 
    {
      Word = SaveFile.ReadWord();
      if (SaveFile.ReadWord() != ";") 
        ABORT("Invalid terminator in file %s at line %ld!", SaveFile.GetFileName().CStr(), SaveFile.TellLine());
      inputfile incf(game::GetGameDir()+"Script/"+Word, &game::GetGlobalValueMap());
      ReadFrom(incf);
      continue;
    }
    if (Word == "Message")
    {
      Word = SaveFile.ReadWord();
      if (SaveFile.ReadWord() != ";") ABORT("Invalid terminator in file %s at line %ld!", SaveFile.GetFileName().CStr(), SaveFile.TellLine());
      fprintf(stderr, "MESSAGE: %sn", Word.CStr());
      continue;
    }
...

But then I think you'd have to add his LoadGlobalValueMap() function before InitGlobalValueMap() in game.cpp. And you might have to add a bunch of other stuff.

I'm pretty sure there's a rate at which monsters spawn, which can be set in the dungeon script and varies from level to level.

Actually, that's pretty good I find it difficult to beat Mr. Enner in any arbitrary game. When it happens for me it's because a whole lot of neat things fall perfectly into place.