Inspired by the Mothership sci-fi horror rpg, I have been thinking about how it might play in a more heroic tone for a science-fantasy game. While it is a d100 system, its quite different from the BRP engine, in that Stats are more important than skills. A skill is a bonus of 10-20% added to a Stat. Key to the arrangement of mechanics in Mothership, is that failed Stat and Save rolls give your character stress, and critical failures (a double roll above the Stat/Skill level, e.g. a 99) trigger rolls on the Panic table, which is full of dangerous complications.
When your typical chance of success on a roll is around 20-50%, players are encouraged to avoid making rolls by interacting with the fiction in a slow but steady way – which works fine until you get jumped by monsters. Stress is used for experience, as you reduce stress gained in adventures, you turn that into improved Stats, Saves, and Skills. So for those who take great risks and survive, there are also good rewards.
Stats
For this hack, I think five Stats are needed:
- Speed (SPD): use this for tests involving perception, initiative, movement, and quick reactions.
- Strength (STR): use this for tests involving brute force, endurance, ignorance, and intimidation.
- Intellect (INT): is used for most skill tests in stressful circumstances unless another Stat is more compelling in the situation.
- Psionic (PSI): used for tests involving psionic talents or “sufficiently advanced” technology. In a fantasy game I would call it Power (POW).
- Warrior (WAR): used for combat tests and warfare (yes it could have been COM for combat, but COM makes me think of Comeliness in the old AD&D Unearthed Arcane. CON for conflict would also work, but is close to Constitution, perhaps BAT for battle as an alternative?).
For a non-horror game, I think the Stats should be higher than in Mothership, so I would let players assign Stat values of 20, 30, 40, 50, and 60. Mothership has Stats cap out at 85, so with the customisation options below, you do not want starting Stats higher than 60.
Saves
Mothership is not to different from BRP, except what might be Endurance and Dodge are merged into Body. Keeping with just three saves:
- Chaos: used to resist mental harm from psionic (or magic) attacks, and to perceive true reality. In Mothership this is called Sanity.
- Will: used to resist loss of control over your actions from situations involving fear, passion, and other emotion surges. In Mothership this is called Fear, but I think Will or Willpower covers a wider range of situations, especially if you want to insert Runequest or Mythras style passions for the PCs.
- Body: used to resist physical harm, including from disease or invasive organisms. Could also be called Thews if you want to lean into Sword & Sorcery genre.
Assign the scores of 20, 30, and 40 to Saves for a horror/pain level similar to Mothership, or fudge the numbers up 10 to 20 points for a more heroic tone.
Wounds, Mana, and Fate
Mothership uses both Wounds and Health for tracking physical harm, with each Wound having 10+1d10 Health, and most characters having two Wounds. Any time you lose enough Health to cross a Wound threshold, you roll on a Wound table for potentially painful complications.
For my hack, I want a bit more certainty around Health, so Health is determined by 10 + STR divided by 10 (round up) for each Wound point.
Mana is the pyschic or magical equivalent of Wounds, and Essence is the equivalent of Health. Unlike Health, you are burning Essence points to fuel any PSI talents that you are using.
When you burn a point of Mana off, you get complications like nose bleeds (minus Health), migraines (plus Stress), conditions that impose disadvantage on checks, or a permanent increase your minimum Stress score.
For my hack, Essence is equal to 10 + INT divided by 10 (round up) for each Mana point.
Fate is a heroic resource to keep PCs alive, and Luck is the equivalent of Health/Mana. You can spend Luck at any time to manipulate fortune before making a roll (e.g. spend a luck point for Advantage) or after a roll (spend luck points to nudge the die result).
When you tempt Fate, however, flip a coin. If it lands the way you call it, there is no effect. If not, you make a roll on the Doom chart of horrible fates for heroes. Perhaps you get cursed by the Gods, lose a few points off a Stat or Save, or have the GM draw a Major Arcana card from a tarot deck to interpret what happens next.
For my hack, Luck is equal to 10 + SPD divided by 10 (round up) for each Fate point.
Character Customisation
Keeping this really generic, although you could customise archetype packages for genre/setting. Each player can choose three of the options below for their character, but each option can only be selected once:
- +5 to all Stats.
- +20 to one Stat.
- +10 to all Saves.
- +25 to one Save.
- +1 Wound.
- +1 Mana.
- +1 Fate.
Having specific trauma responses to stress and panic is a bit harder to make generic. I might cut them entirely for a heroic campaign, or build a unique one for each PC based on discussion with the player.
Skills
Not much to say here, as the skill list should be tailored to the genre and setting. Broad or apprentice level skills should be +10% to checks, defined or expert skills should be +15%, and specific or master skills should be +20%. Adding in some perks or stunts for Master skills is quite appropriate. Skills greater than 20% might make sense if you campaign is aiming for transhuman or demigod power levels.
So Militia Training is +10% to WAR checks, while Melee Weapons is +15%, and Long Spear is +20%. Perhaps your hero might acquire and learn to wield a Spear of Destiny at +25%.
For our science-fantasy game you might have Psionic Training at +10% to PSI checks, Telekinesis at +15% and Soul Blade at +20%. Perhaps you character learns alien secrets and learns to manifest the Dual Soul Blades at +25%.
Mythras or Call of Cthulhu have some good packages of skills, and while Mothership only hands out a few skills at the start, for a more heroic level of play I think you could give out more skills to starting PCs, e.g. two Master, two Expert, and four Trained skills.
Vices
I would be temped to take the list of Vices from Blades in the Dark and have players pick one for the PC to indulge in to reduce Stress in downtime actions.
Mechanics Are Easy 