NOTE: *I ended up writing the barest minimum of scenario and a whole bunch of system for this, which was the opposite of what I intended, so I’m throwing this out there unfinished. Most notably, the equipment section is unwritten. It’s a rather kludgy hack of Yochai Gal’s Cairn with some major influence from Sean McCoy’s null.HACK.

Hopefully there’s one or two things here to pick at for anybody wanting to run OSR-ish games with a Nihei-influenced vibe. In the meantime I’m going to keep hacking away at a far future mythic sci-fi setting for OSR play.*

Tomb City Orphans

The concrete hallways and chambers down here are dark and deathly silent. Every echoing step you take rings your presence. You wonder where everyone went - this place used to teem with people, but after you awoke, they’re all gone.

You can’t stay here. Soon enough you’ll run out of power altogether and you’ll be at the mercy of the things that thrive in absolute darkness. The few of you who are left will need to venture out through the long tunnels into the unknown. Maybe somewhere in the depths you can find others like you. Maybe The Surface is more than just rumour.

It’s not much to go on, but right now it’s the closest thing to hope that you have. Time to go.

The Basics

Tomb City Orphans is a roleplaying scenario set in a distant future of underground ruins of crumbling concrete, where humankind has long since disappeared. Players each take on the role of a lost inhabitant of this place, usually robotic in nature. It assumes basic knowledge of how to run and play in an RPG and a reasonable degree of trust between participants. It uses a D20 roll-under system for task resolution and is a hack of Cairn’s rules.

Character Creation

Choose a background:


Human-like but designed by humans, you cannot escape your own uncanny valley, but live nonetheless.


Shards of stray consciousness jammed haphazardly into frame. A collage of a lost soul, full of memories of uncertain provenance and body that is not your own.


Function and logic, both ill-at-ease with and reverent of your more human-passing companions. Most at home when provided a clear purpose and task.


Polymorphic, self-modifying code that imitated humanlike personality traits, you now find yourself having developed a consciousness as a means to survive.


Roll 3d6 three times and assign the scores to Strength (STR), Dexterity (DEX) and Perception (PER)

Roll 1d6 for Hit Points (HP)


Select three skills from the below table. If the skill is applicable to a task or action for which the outcome is uncertain, the referee may let the player roll at advantage.

Marksmanship | Bartering | Athleticism |
Stealth | Archaeology | Intimidation |
Scavenging | Field repair | Demolition |
Close-quarters combat | Navigation | Esotericism |
Network penetration | Mecha piloting | Systems analysis |
Empathy | Deception | Evasion |



Attacking using a weapon requires a player to successfully roll on one of their stats. This is defined per-weapon, but as a general rule, melee weapons such as swords, axes or glaives require a STR roll, ranged weapons such as pistols, shotguns or SMGs require DEX, and long-range weapons such as rifles and railguns require PER.


Armour acts as an extra layer of HP, and is always deducted first if a character is hit. However, critical hits ignore armour. When a character’s armour is reduced to zero, the armour breaks.


When attacking, take note of the stat your weapon uses and attempt to roll under your score. If you succeed, you deal 1HP damage. If the result is 4 or below, you deal 1d6HP critical damage.

All normal weapons deal 1HP damage, explosives, exotic and super-heavy weaponry always deal critical damage on hit.

If attacking unarmed, roll for STR. Your opponent must succeed a STR save or take 1HP damage.

When a PC is dealt critical damage, they should roll on the below table and subtract the score from their stats as appropriate.

1 Arm severed -1d6 STR
2 Direct hit to body knocked prone
3 Cranium shattered -2d6 PER
4 Neuroptics disrupted -1d6 PER
5 Somamotors glitched -1d6 DEX
6 Leg severed -1d6 STR, immobilised
7 Side of torso blown off -2d6 STR, -1d6 DEX, knocked prone
8 Internal battery rupture -2d6 STR, -2D6 DEX, knocked prone, explosive
9 Processor array destroyed instant death
10 Black box destroyed cannot be recovered after death


If HP, STR, DEX or PER are reduced to zero, a character becomes broken, and cannot perform any actions by themselves until repaired. If any two stats are reduced to zero, they die. However if intact, a dead PCs black box can be recovered and transplanted into a new body-frame. During this process, the character’s personality and memories remain intact, but new stats for HP, STR, DEX and PER must be rolled.


During downtime, any character can attempt to field-repair another character that has been broken. The outcome of this is always uncertain. If the action succeeds, the repairer can re-roll the broken stat. If the action fails, the repairer instead rolls 1d4 for that stat.

April 3, 2022

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