This is actually a rather "I wish" request which might
be difficult to implement, but I just thought I could
submit the idea.
Basicly, Slashem/Nethack are rather "unsurprising" in
the overall aspect of exploration of dungeon levels.
The idea behind subplots is to add some spice to
dungeon levels by introducing the fact that peaceful
characters might actually have something to ask of the
character and introduce some kind of subplot. A few
examples:
- A peaceful hobbit asks for a 'wedding|engagement
ring' he has lost in the level and is trying to recover.
- A peaceful ogre mage asks for a given spellbook
- A peaceful elf asks the player to help a comrade in
arms which is being besieged by monsters
- A peaceful gnome has lost his luckstone
[ the subplot of 'peaceful X wants Y' could actually be
done by the RNG ]
Obviously, the character has to #chat to obtain this info.
The item (or situation) that is introduced should be
available in the level (somewhere), and the player
character has an specific time before the NPC
dissapears. All have a special teleport level scroll,
enchantment or trap (a one-way portal?) they will use
if attacked of if the mission expires.
There is no added benefit to the player but a great
reward might be hinted (an artifact): Lawful characters
that do not complete the subplot in time might angry
their god, chaotic characters that do might get their
god angry too.
This feature might be useful (if a small reward was
granted) for lower player characters and need not be
done in all dungeon levels. It could be constricted to
dng < 10 to avoid powerful characters from wasting
their time in petty plots.
A very interesting idea, but the coding of this would be (beyond my capacity surely) but very difficult indeed!
The only advice I would have is look at all the NPC's (nonplayer characters like shopkeepers, oracle, gypsy, magic memory vault guards, demon guardians that you can bribe, and maybe the convict bribe guard code) to determine how you could get a (hobbit asks question instead of guard asks name) or something, but the trigger and spawn of a specific item (after acceptance of the quest) might be a bit more difficult, maybe even impossible.
Maybe you could ask the Creator of A.D.O.M. how he got quest possibilities and quests and item/monster/cave spawns to work.