In front of you, you can see a big chunk of some weird metal alloy, that looks shiny, yet matte, strong but very light. It’s nothing like you have ever seen before. Tricking, dripping and oozing from it onto the stone ground of the cavern, is a thick, black glossy substance. It looks very much like that which was drooling down from the eye sockets, of those shambling creatures you met back in one of the rooms of the cairn above...
Black oil is the main “antagonist” of my Isle of Rána adventure. I wanted to create an adversary, different from a “BBEG” or a mad wizard or demon, or anything that has a true corporal body and whose intelligence mortals can easily comprehend.
Black oil is an alien substance, intelligent, alive in a way, which is looking to possess bodies and overtake the isle. Ultimately its goal is to pave the way for its creators to come and colonize the world. ...Yes I watched the X-Files as a kid, why do you ask?
One of the mechanics I created for the Isle of Rana is the Black Oil infection. Delving deeper into the dungeon and coming in contact with the Black Oil and those it possesses, raises their level, slowly infecting them. This at first might have positive effects on the player's strength, it can lead to them getting first into a catatonic state and eventually being completely taken over by the Black Oil and becoming another Oil spawn minion.
Story-wise – Black oil leaked into this world from a crashed spaceship and that is where it still exists. In the adventure, the party will be looking for pieces of a mythical artifact that is meant to bring fertility, food and life - a cornucopia or Sampó. is looking for in the Rána adventure was “given” to the original heroes of the isle, by the oil. What first seemed like a gift, soon turned to become a curse. The artifact was broken into pieces and buried deep in the oil. Black oil as well as the pieces of mysterious metal (remains of the crash) were disposed of. But the ancestors did not know of all of them. And time passes and with it, certain things fade into memory.
Meanwhile, the Black Oil has slowly been taking over bodies of the living and dead, controlling them, creating an army made up of shambling corpses oozing black oil, from its cavities, flying creatures which once perhaps were bats or other fliers, oozes, slimes and whatever else came it’s way in the depths of the earth.
Black Oil mechanics
Infection levels
PC has a feeling of mild chills and cold. PC also feels stronger +1 to STR.
Coldness deepens. The infected PC need to be near a source of heat or warmth or suffer fatigue.
Gradual blackening of the eye whites of the infected PC
Advantage / +5 to strength checks including to hit. Veins in the body of the infected begin to blacken
Advantage / +5 to dexterity checks including to hit. Lips of the infected turn black.
The substance thickens and grows to take control. Disadvantage / -5 to all attack rolls when facing any Black Oil monster.
Spreading the infection. The infected coughs and spits out Black Oil, uncontrollably at random times, trying to infect those nearby.
The infected enters a comatose or near-death state as the Black Oil takes control.
Now it’s too late. The infected PC has been fully taken over by the Black Oil and awakes from its coma as an Oil Spawn minion – retains the PC's class, level and abilities.
Gaining Black oil levels
Automatically gain one Infection level, when entering a room with a source of Black Oil.
Every three turns spent in a black oil source room increases the Infection level by one.
Gain one infection level, by direct, skin to oil contact – touching a puddle of Black Oil, or an item or creature coated in Black Oil.
Ingesting the oil automatically gains two Infection levels.
If a character takes more than half of their HP damage from a single oil spawn creature, gain one Infection level.
Recovery:
Long rest lowers one infection level.
Resting alone cannot progress black oil levels below the thresholds of Infection levels 1 / 3 / 6.
A successful remove curse ritual lowers the Infection level back to level one.
If a character gets to Infection level eight and resets down to level one through a cure curse ritual, the Infection level grows automatically by one level each day. Every subsequent makes the Infection levels grow exponentially faster – A second remove curse increases the level gain to two per day, etc.
To fully purge a PC from the Black Oil the party will have to explore the fourth Cairn – I haven’t thought of the cure yet to be honest – sooo you can make up anything, in case you wanna use this.
This whole entry is actually a prelude, to the first dungeon I want to put out for free. I realized that I perhaps should introduce the Black Oil and it's mechanics.
More on Rána: Check out The Magical Materials and their mechanic article
