Roll-your-own rituals for old school D&D

Ultima 3: Exodus Cleric

Ultima 3: Exodus ClericWhen Fantasy Heartbreaker launched, it was about 80% an OSR D&D blog. The focus has drifted in the years since. Among other things, I don’t run or play as many OSR games as I used to. However, lately I’ve been tinkering again, and I thought I’d share the results of my work.

This system was originally designed for a house-ruled Swords & Wizardry, but shouldn’t be dependent on any quirks of that system.

The system flows from a few suppositions about old school play:

  1. Resource management is a major factor in success
  2. Spells are a resource that allows you to avoid expending other resources
  3. Time is also a resource

Therefore, the metrics all revolve around how much effort the ritual replaces and how much time you’re willing to put into it. Sacrifice mechanics (of PC HP and potentially NPC HD) make using the system a little bloodier, a little less abstract.

Ritual Magic

Do your spells need more power or pizazz? Rituals allow adventurers to perform magic beyond the abilities of a conventional spell.

Planning a Ritual

The power level of a ritual is based on the amount of labor it saves.

A round An encounter An adventure An invasion
An adventurer 0 1 4 8
A party 2 3 6 12
An army 4 5 8 16

That power level is modified by preparation that goes into the ritual.

Modifier Preparation
-1 An hour’s incantation
-2 A night’s preparation
-4 A week-long ordeal

The cost is 1 HP per HD of targets affected. MP costs can be absorbed from non-caster ritual participants. For example, a fighter can provide HP to a ritual being cast by a cleric.

If a living sacrifice is used, its HD can be subtracted from either the power level of the ritual or the HP cost. This is a very unheroic thing to do, but is noted to shed light on the modus operandi of those ubiquitous demon cultists a hero must smite on their adventures.

Performing a Ritual

  1. Declare the caster and all willing participants.
  2. Perform all preparations.
  3. Determine the power level modified by preparations.
  4. Determine the HP cost.
  5. Make any sacrifices.
  6. Subtract the total HD sacrificed from either the power level or the cost.
  7. Subtract the HP cost from the willing participants’ HP totals.
  8. Roll 1d20.
  9. If the roll is under ((caster level + Wisdom) – power level), the ritual succeeds. Otherwise, each participant must save against a backlash determined by the DM.

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