OSR to Perils & Princesses Conversion Guidelines​

The follow guidance can be used for converting from B/X, OSE, or similar OSR adventures to Perils & Princesses. This provides a baseline, mostly for creature stat blocks, and should be adjusted as appropriate. I used this procedure to convert Winter's Daughter.

• HP = 3 + HD (± 1 to 3 if they are unusually susceptible or resistant to physical injury).

• SAVE = 8 + Level (± 1 to 3 if they are unusually fast or slow, strong or weak, resistant to or vulnerable to magic or poison effects not otherwise covered by special abilities or notes).

• Armor = [0 for none, 1 for Leather, 2 for Chain, 3 for Plate]
  • With Descending AC [9 = none, 7 = Leather, 5 = Chain, 3 = Plate]
  • With Ascending AC [10 = none, 12 = Leather, 14 = Chain, 16 = Plate]
    

• Attacks generally convert one-to-one. Multiple attacks (e.g. 1 x claw and 1 x bite) may convert one-to-one, or roll all and keep the highest.

• Spells - Assign a number of GD equal to half the creature's HD rounded up. Then, either…
  • Pick an existing spell with a functionally or thematically comparable effect. For example, Hold Person or Web can be replaced with Bind or Tangle, replace Locate Object with Mine!, or Invisibility with Fog.
  • Convert the spell by replacing Duration, Range, Damage, and number of effected creatures with [SUM] and [DICE] as appropriate. For example, Charm becomes Range: [DICE], Save WITS - A creature will follow any commands that will not reasonably cause itself harm for [SUM] days. The creature can roll to Save each day to end the spell early. 
  • Invent a new spell using an existing spell as a template. For example, reflavoring Magic Dart as Snowball, Range: Stone’s Throw - Fire [DICE] snowballs that each deal an amount of damage shown on the individual dice spent. Cannot be dodged.
    
  • For more P&P compatible spells check out Shadow & Fae 2e.

• Ailments and effects generally last for some amount of “minutes” or “rounds” (about 10 seconds), and/or are cured by Spending Time generally or at a specific narratively appropriate activity.

• Ability or skill challenges may be replaced by Spending Time at the task to overcome it.

• Ongoing effects may be converted into Curses with a narratively interesting cure. Use existing Curses as a template.

• Convert magic items into Relics, Wondrous Items, and Enchanted Weapons, using those existing items as templates.

• Treasure: 1 gold piece is about 1 silver piece.

This work was independently produced by Joey V and licensed under CC BY 4.0 and is not affiliated with Outrider Creative LLC. Perils & Princesses is copyright Outrider Creative LLC.

Art is by Virginia Frances Sterret.