One of my biggest challenges making an MMORPG with a small team was to come up with a system that could create replayable content without the need to hand place everything.
The "Living World" system is the solution I came up with to deal with the creation of NPC cities and villages, dungeon populations, open world encounters and quests.
The core concepts is that Factions are generated on demand, and act as a Strategy Game AI. Having an objective at hand (For instance, building a castle), it decides through the use of a GOAP-based decision system how to do it based on what is at it's homebase's reach, which may include hiring players to gather resources or build units to scout for an Iron Mine or a forest in which to build a Lumberyard.
When such a Point of Interest (POI) is captured, it is converted into a Village (if the Faction is a Civilization) or a Lair (if the Faction is a Horde). That POI is then populated by that faction's NPCs, buildings and objects until it's heart (a boss or object) is destroyed. It also generates relevant encounters in the surrounding area.
In that way, a player may come across a web-covered corpse near a tree and immediately know giant spiders must have taken the nearby forest or mine. Nearby cities and villages may also call for help, asking for players to deal with the threat, collect spider eggs for a magic potion or find a missing pig that strayed too far from their fair.
The Living World system is been designed and developed in modules so that it can be tested in isolation and enhanced on demand. In that sense, the Lair mechanic described above can work independently of the Faction AI, Quest system or the city building mechanic by randomizing new NPC Factions every time the previous one is destroyed.
I designed this creature and encounter for the prealpha version the MMORPG Profane as it's first world boss.
Con Hit was prototyped internally, then added to closed alpha as seen on the footage made by one of the game's clans.
Data gathered from Pre Alpha was used to adjust a future version of the creature as well as other world bosses to come.
During the night, players would see dust trails in the desert. If they dropped a special kind of fruit near one trail, all trails would scene, then the create would burst out of the sand.
There were three stages to Con Hit:
At full health, Con Hit attacks with a melee bite, then sinks underground and bursts out under the ranged enemy with high aggro;
At 75% health, between bite attacks Con Hit releases one minion per engaged enemy. The minion can be killed, but explodes upon death or contact.
At 40% health, Con Hit replaces bite attacks with a ranged spit attack at random ranged targets, leaving a lasting pool of acid damage
On death, Con Hit doesn't drop equipment, but the main ingredients of two of the game's most powerful consumables: explosive potions and explosive arrows.