Sunday 1 August 2021

Creating 15mm Sci Fi Rules "The Forgotten" - Design Brief, Game Requirements

 This came from a desire to experiment with a shared resource mechanic and a desire to use my 15mm sci fi for something that isn’t merely Vietnam-in-space or rebadged Rogue Trader.

The fluff: 

The Rapture spoken of in the Book of Revelation has come. The holy have ascended to heaven, and the earth has been destroyed in fire. However, Revelation didn’t mention the unbelievers who were in space stations, asteroids, or terraforming colonies….

Twenty years on, darkness and horror stalks the remnants of humanity – the “Forgotten”. The Forgotten form factions, warring for valuable resources, usually under the patronage of powerful demons who compete for resources, followers and prestige. The small populations of these colonies and bases do not support large armies. Instead, small special ops teams are aided by their demonic patrons in desperate strike missions and boarding actions, as resources (and potential vassals) are rare and previous. Something along the lines of Alien meets Mass Effect and Demon: the Fallen.

Possession Mechanic

Demons are incorporeal spirits, only able to influence the world via a willing Host.  A demon can grant a portion of its essence to a Host, "possessing" them and boosting them to inhuman feats of strength and endurance, channelling miraculous powers. However this is not without risk – when a Host is destroyed, any demonic essence within is banished, leaving the demon weakened compared to its rivals until it can be later restored through complex rituals.

Another twist in this future is that the weaker a character’s Will, the easier they are to possess; but the weaker also their morale, resolve and susceptibility to hostile possession.


I want to keep the mechanics (activation, movement, combat, morale) simple and familiar so as to focus on possession mechanics without too much mental overload. Currently I am using 15mm so I am using them in fire teams of 2-4, as the 15mm infantry look better in groups rather than as stand alone pieces.

I want the game to work as a standard, simple cyberpunk/near future game first; then “bolt on” possession mechanics on top. These possession mechanics will work a little like an off-table Warmachine warcaster. Hacking and drones will be a separate layer which is independent of the possession mechanics (i.e. mechanical objects cannot be buffed or debuffed by spirits) but will be more basic.


15mm Models.

I’m planning on “squad-to-to-platoon” scale - the basic “maneuver unit” is fireteams of 2-4, and the rules should handle 4-8 fireteams – so between 8-32 models.


A handful of of d6s at the moment (may later switch to d10s); Tape measure (2” = 5cm)

A d10 is handy for scatter dice (the top of the triangle of the top number shows direction)

EM4 tokens for HELD (white); SHOCK (yellow); WOUNDS (red); and POSSESSION ESSENCE (black), Stealth (green) which should fit under the 15mm models bases neatly.

For testing, I'm using a 4x4 or 4x3 table with plenty of cover.

Dice Rolling

Usually you need to roll equal or above a stat to succeed i.e. if your SHOOT is 3, you need to beat 3+ on a d6 to score a hit.

Character Stats

(M) Move = how fast and far you run

(CS) Combat Skill = training, reactions, initiative under fire – roll equal or above to pass

(SH) Shooting = firing accuracy – roll equal or above to hit

(CQC) Close Quarter Combat = hand-to-hand skill – roll equal or above to hit

(PHYS) Physique = muscles, physical ability – modifies CQC damage and some moves

(DEF) Defence = combination of natural resilience, bulk and armour

(WIL) Will = willpower, morale, resolve – also used to resist demonic influence

A trained, baseline human marine in light armour would be

M 4”, CS 4+, SH 4+, CQC 4+, PHYS 3, DEF 4, WIL 4+.

A “normal” assault rifle is:

 12/24/36, RoF 3, Damage 4.

Bot/Remote Stats

(CYB) Cyber = processing power, AI capabilities, bandwidth, i9 vs i3, etc

(FIRE) Firewall = both software and hardware defence

As you can see, there's nothing spectacular here. So far, so very 40K. I will probably later switch to d10s for all resolution to make things more "granular." 

Next up, activation, detection and movement.


  1. I still cannot believe you’re back and with so many juicy updates!
    I really like this rules and background you’re working on, something like “40k meets Infinity”.
    This is great I’d say. Would be great to see d10s in this 40k for grown up.
    The d20 in Infinity often receive a + or -3 that is, basically, what would be a +1 on a d6 but using a d20. I think a d10 is a good compromise and help to read the chances (the probability of success, I mean) more easily.
    I stay tuned for more goodies!

    1. Btw, I actually have made a 40K-meets-Infinity with my modern pulp rules (i.e. it's basically d10 Infinity with some limits on activating too many times in a row)

      Hmm I'll have to dig them off my old SSD...

    2. Uhm, I’m curious which limitations did you put in place to discourage multiple activations ๐Ÿ˜‡

    3. From memory, a single model could only use half the total team tokens to activate, and it could not use them successively i.e let's say there is 5 guys on the team; Ratmaul, W, X, Y and Z; or 5 total activations

      Ratmaul can have 3 of the 5 total activations but they cannot be successive i.e.

      Ratmaul W Ratmaul X Ratmaul <- is allowed

      Also there was a SoBH-esue roll to see how many actions you could take per activation there wasn't 2 automatically like Infinity

  2. Yeah - I actually ditched d6s when I started the next stage as they're so clunky (you have to do extra rolls for saves or throw handfuls as modifiers cannot fit on the dice)

    d10s are my preferance as it's easy to calculate odds when designing rules (I think I originally went d6 merely as there was a handful on my desk and I was too lazy to go out into the cold shed)