Showing posts with label OSR Combinations. Show all posts
Showing posts with label OSR Combinations. Show all posts

Saturday, March 14, 2026

Further Thoughts On Combining Warriors of the Red Planet and 13 Parsercs Rpg - The Barsoomian Way Part II

 


Merging 13 Parsecs (a solo-play toolkit for sci-fi exploration) with Warriors of the Red Planet (a Sword & Planet OSR game) creates a gritty, atmospheric "John Carter meets Rogue-like" experience. This blog post picks right up from Combining Warriors of the Red Planet and 13 Parsercs Rpg - The Barsoomian Way



Since 13 Parsecs is designed for a "used future" aesthetic and Warriors of the Red Planet (WRP) is focused on pulp planetary fantasy, you’ll be playing in a setting where high-tech salvage meets ancient, dying civilizations.


1. The Core Mechanical Bridge

The primary challenge is reconciling the Health/Combat systems.

  • Hit Dice vs. Hits: 13 Parsecs often uses a "Hits" or low-HP system. Stick to the WRP Hit Dice and Armor Class for combat to keep the pulp "hero" feel alive.

  • The 13-Day Clock: In 13 Parsecs, you have a limited time to pay off debt or reach a goal. In a Red Planet setting, rename this the Oxygen/Water/Rad-Cell Clock. If it hits zero, your air or hydration fails in the wastes.

Converting Character Stats

WRP Attribute13 Parsecs EquivalentUse Case
StrengthProwessMelee, lifting, brute force.
DexterityCoordinationPiloting sky-ships, dodging traps.
ConstitutionEnduranceResisting thirst, radiation, or exhaustion.
Mental (Int/Wis)Logic / IntuitionDeciphering ancient Martian tech.

2. Setting the Scene: The "Dying World" Hex-Crawl

Use the 13 Parsecs procedural generation tables to map out the Martian wastes instead of deep space.

  • Sector Generation: Instead of star systems, each "sector" is a City-State, Ruined Spire, or Silt Sea.

  • The Ship: Your "Ship" in 13 Parsecs becomes your Sky-Galleon or Thark Beast-Train. Upgrades apply to its speed across the desert and its mounted radium cannons.

  • The Goal: You aren't just looking for scrap; you're looking for Life-Water or Atmosphere Plant Parts to save your dying enclave.


3. Adapting the Tools

The beauty of 13 Parsecs is its Oracle and Encounter tables. Here is how to reskin them for the Red Planet:

  • Encounters: When the toolkit says "Space Pirates," read Red Martian Raiders. When it says "Xeno-Monster," read Great White Ape.

  • Loot & Salvage: Instead of "Circuitry" or "Reactor Parts," you find Psychic Crystals, Orichalcum Scraps, or Radium Vials.

  • Social Interactions: Use the WRP Reaction Table alongside the 13 Parsecs "Motivations" table to see if the Barsoomian princess you just rescued actually wants your help or is leading you into a trap.


4. The "Science-Fantasy" Math

If you encounter ancient machinery or need to calculate the trajectory of a falling moon, keep the math consistent with WRP's OSR roots.

For example, if you are jury-rigging a power cell and need to determine the energy output ($E$) based on remaining Radium mass ($m$) and a decay constant ($k$):

$$E = m \cdot e^{-kt}$$

(In-game, just roll under your Intelligence/Logic score, but the flavor text should feel like high-concept pulp science!)


5. Gameplay Loop

  1. Departure: Leave the safety of a domed city (The Hub).

  2. Travel: Use 13 Parsecs travel rolls. Each "Jump" is a day’s trek across the crimson sands.

  3. Discovery: Use the Oracle to determine what you find (A crashed scout ship? A nest of Thoats?).

  4. Combat/Conflict: Resolve using Warriors of the Red Planet rules for that fast-paced, lethal OSR feel.

  5. Return: Sell your loot, recover your HP, and tick down your 13-Day Doom Clock.

To capture the "high-crunch" procedural feel of 13 Parsecs and the planetary romance of Warriors of the Red Planet, this d100 table is designed with "Sub-Tables" and mechanical hooks.

This ensures that a single roll provides both narrative flavor and a direct mechanical challenge for your OSR-style campaign.


The Red Planet d100 Master Encounter Table

d100Result TypeEncounter DescriptionMechanical Hook (WRP / 13 Parsecs)
01-05The Void-CallA psychic echo from an ancient, dying Moon-Mind.Save vs. Mental or suffer 1 level of Sorrow/Stress.
06-15Thark War-Band2d6 Green Martians on Thoats, scouting for water.Reaction Roll -4 if you have visible water or radium.
16-25Atmosphere LeakA pocket of "Thin Air" or a ruptured ancient pipe.13-Day Clock ticks down 1 extra step due to exhaustion.
26-35Radium ScavengersRed Martian drifters stripping a crashed Sky-Galleon.Logic Check to salvage 1d6 Radium Vials.
36-45Great White ApeA starving, four-armed behemoth in a ruined archway.Surprise Check. High AC and 3 attacks per round.
46-55The Silt-ShifterA massive, burrowing crustacean mimicking a sand dune.Treat as a Hazard. Coordination check to avoid ship damage.
56-65Ancient RelicA pulsating Orichalcum obelisk covered in Oghamic script.Roll on the Specialized Tech Table (see below).
66-75Dust StormA "Static-Red" storm that fries electronics and optics.All ranged attacks at -4; movement reduced to 1/4.
76-85Imperial ScoutA sleek, chrome-plated flyer from a distant High-City.Intuition Check to hide before they spot your "Ship."
86-95The Water-WitchA rogue psychic offering "Life-Water" for a high price.Cost: 1 permanent HP or a Rare Salvage item.
96-00The Glass-Sea GhostA phantom ship from Mars’ lush, watery past.Event: Gain a temporary "Past-Life" Trait or Perk.

Specialized Tech Sub-Table (d10)

If you roll 46-55 or Salvage a Relic, roll a d10 to see what the "Crunch" is:

  1. Gravity Bracers: +2 to Coordination/Dexterity for 1 hour.

  2. Neural-Whip: Target must Save vs. Paralysis or be stunned for 1d4 rounds.

  3. Solar-Still: Converts 1 unit of Radium into 1 week of Water.

  4. Psionic-Emitter: Can cast Telepathy once per day (Mental Check required).

  5. Radium Flare: Blinds all biological eyes in a 50ft radius.

  6. Thoat-Whistle: Summons a wild mount, but has a 10% chance to attract a predator.

  7. Crystal Lens: Grants +2 to Logic checks when deciphering ancient maps.

  8. Void-Suit Patch: Instantly repairs 1 "Hit" of hull damage to a Sky-Galleon.

  9. Oghamic Tablet: Teaches one random "Science-Fantasy" Spell or Maneuver.

  10. The Dead-Hand: A cybernetic graft. Roll d100 on your Graft Table to install.


Environmental Hazard Logic

For procedural travel across the Red Planet, use a Depletion Die for your essential resources (Water/Radium).

If your group travels through a High-Radiation Zone, calculate the dosage ($D$) relative to the time ($t$) and the intensity constant of the sector ($R$):

$$D = \int_{0}^{t} R(x) \, dx$$

Pro-Tip: If the total $D$ exceeds your Endurance/Constitution, you take 1d6 permanent attribute damage until you reach a High-City Med-Bay.

Sunday, March 8, 2026

Combining Warriors of the Red Planet and 13 Parsercs Rpg - The Barsoomian Way



Integrating Warriors of the Red Planet with Thirteen Parsecs (often referred to as 13P) is a very natural fit, as both games are rooted in the "Old School" design philosophy.



While they use different core engines, their shared DNA makes them highly compatible for a "Sword & Planet" campaign.

System Compatibility

  • Engine Foundations: Warriors of the Red Planet is a traditional OSR (Old School Revival) game based on the original fantasy RPG rules. Thirteen Parsecs uses the O.G.R.E.S. engine (Old-school Generic Roleplaying Engine System).

  • The "Feel": Both systems prioritize high adventure, ruling-over-rules, and a lean mechanical footprint. Because Thirteen Parsecs is designed to be a "New Class of Old School," it shares the same bounded accuracy and power scales as Warriors of the Red Planet.

How to Play Them Together

Since Thirteen Parsecs is a toolkit for any sci-fi subgenre, you can use it to "crunch up" the more minimalist Warriors setting:

  • Character Archetypes: You can easily swap classes. For example, use the Mystic Knight or Psychic from 13P to replace or augment the Mentalist in Warriors.

  • Starship & Tech Rules: Warriors is lighter on technical vehicle rules. You can use the robust Starship Creation and Combat rules from Thirteen Parsecs to handle the high-flying airships of Mars or Venus without breaking the math.

  • Conversion: Since both use standard attributes (Strength, Dexterity, etc.) and similar Armor Class/Target Number logic, you can usually port monsters and NPCs between them with zero math. If a Martian creature in Warriors has a 4 HD (Hit Dice), it will function effectively as a Level 4 threat in 13P.

Why Combine Them?

If you find the "Original Fantasy" bones of Warriors a bit too restrictive for high-tech encounters, Thirteen Parsecs provides the Skill System and Career Training that can give your planetary heroes more specialized utility outside of combat.

Since both games are built on the foundational "Old School" six-attribute chassis, you can port characters with almost zero math. The primary goal is to map the flavor of Warriors of the Red Planet (WRP) onto the slightly more granular 13 Parsecs (13P) engine.

1. Attribute Mapping

Both systems use the standard range (3-18). You can port your Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma directly.

  • Saving Throws: 13P uses a unified "Save" based on the O.G.R.E.S. engine. Use the character's Level + Attribute Modifier to hit a Target Number (usually 15 for difficult tasks).


2. Class Conversion Table

Because 13P is a toolkit, you can "build" a WRP class using its archetypes and career paths.

WRP Class13P ArchetypeSuggested 13P Career
Fighting ManSoldierMercenary or Gladiator
ScoundrelOperativeSmuggler or Scout
ScientistTechnicianEngineer or Medic
MentalistPsychicMystic or Telepath

3. Integrating Features

To make the character feel truly "Red Planet" while using 13P rules, apply these three mechanical tweaks:

  • The "Barsoomian" Perk: Every character from WRP should receive a +1 bonus to all Athletics and Leaping checks in 13P to represent the lower gravity of a dying world.

  • Weapon Scaling: Use 13P's weapon damage (e.g., 1d6 for light, 1d8 for medium). Treat WRP Radium Pistols as 13P Blaster Pistols, but keep the WRP "Misfit" rule (exploding on a natural 1) to maintain the high-stakes feel of ancient tech.

  • Mentalism vs. Psionics: Use the 13P Strain system for Mentalists. Instead of WRP's "Daily Uses," allow the character to push their powers by taking 1d4 non-lethal damage per level of the effect used beyond their safe limit.


4. Health and Armor

  • Hit Points: You can keep your WRP Hit Points as-is. Both systems scale similarly per level.

  • Armor Class: 13P typically uses Ascending AC. If your WRP character has a Descending AC of 5, their 13P Armor Rating is 15.