Hello!
Off the back of my recent stint playing an AMPC, I have identified a number of areas where I feel small tweaks or additions to our current systems could enhance (A)MPC play.
The Locate Function
Currently the Locate function allows monsters to locate in very broad terms, where players are.
One of the challenges of playing a monster is finding people to menace. Knowing there are X many people in Vallaki is good, but the Vallaki zone encompasses a lot of areas. Finding people, even with Locate, can be like finding a needle in a haystack.
My suggestion would be to give more detail about player locations if the monster is within the same zone. So, if the monster is in Vallaki, @locate could break the Vallaki zone down into wards, outskirts, lakeshore, farmlands, etc etc. This would enable monsters to find players easier, reducing time wasted either waiting or wandering.
Set-dressing and props
The @mark function does not persist through area resets. This means that a monster cannot set up elaborate clues, descriptions or scenes too-far ahead of time, or with the intention of giving something players to find when they're not online. I suspect many of my lovingly-crafted clues were never seen.
Monsters could be given a way to set marks that do persist through area resets. Alternatively, monsters could have a way of setting a limited number of placables, such as blood or slime spatters in much the same way that the carpentry kit works. These would persist through area resets.
Minions
Monsters have the ability to control certain types of NPC based on their template. This is a great thing! .. As long as you can find the right type of monster to control.
Ghouls, Wights and the exotic lycanthropes have a disadvantage in this respect compared to the other templates.. because the monsters of their kind (ghouls and wights), don't appear in many dungeons, and those dungeons may be quite far from their place of activity.
In addition, monsters could have the ability to summon a low number minions to them, which could then be put under control (or just left to wreak havoc). I like the idea of a wererat being able to summon a carpet of rats, or a werewolf calling a pack of hungry wolves to their aid.