Unless I’m truly going to write a system from scratch, I think it would be wise to start with one system and gradually mold it into this Fantasy Heartbreaker of mine. The primary benefit of using an already existing system to start with is that the game is, at least in theory, always in a playable and testable state.

Something to consider in a base system is compatibility with the many supplements out there in the OSR space. I intend for my Fantasy Heartbreaker to be broadly compatible with BECMI and AD&D supplements, so it makes sense to use one of these as a base.

Old School Essentials is a cleaned up version of the Basic/Expert set, which seems like an ideal place to start. It has broad compatibility with BECMI and AD&D as well as most everything else in the OSR world.

With a “base” system chosen, let’s tackle a few of the problems me and my players have with old school gaming in general.

Different ways of using the same dice…

I’ve run OSE for my players for quite some time now and they still find themselves confused as to how to roll an attribute check or a saving throw. They know they need to use a d20, but they can never remember when to use roll over or roll under mechanics.

It’s something I see with other groups as well, so it doesn’t seem to be an isolated problem.

I’ve come to the conclusion that all resolution mechanics using the same die, need to function the same way. In this case that means all mechanics using a d20 need to be consistently roll under, or roll over.

Difficulty Checks and Target Numbers

Something I’ve always struggled with is coming up with target numbers for a given obstacle in a way that is consistant from day to day and session to session. In practice I’ve found that target numbers will vary with my mood, how tired I am and how well the session is going. I’ve witnessed other GM’s run into this problem as well when playing at their tables.

Castles & Crusades largely solves this problem with it’s SIEGE engine where the target number for a roll is 15 + Level of the Obstacle, (ignoring something C&C calls “Primary Attributes”).

A Core Roll

In short, we’re introducing a unified “core” roll to our Heartbreaker.

• Player facing rolls are: 1d20 + Character Level + Attribute Bonus

• Target numbers for Attribute Checks and Saving Throws can be unified to be 15 + NPC Level.

• In circumstances where a player may have an advantage in a given situation, the player rolls twice and uses the better result.

• In circumstances where a player may be at a disadvantage in a given situation, the player rolls twice and uses the worst result.

Target numbers are consistent and the d20 is used the same way, every time.

Keeping the Game Playable

Our new “core” roll currently breaks OSE’s Saving Throws. While I intend to make some fairly large changes to the Saving Throws in the system, let’s make a quick change to keep the game playable and testable while we work on it. We’ll toss out OSE’s Saving Throws entirely, and instead use Ability Checks, with each Ability governing different domains.

• Strength: Paralysis, petrify and constriction

• Dexterity: Breath attacks and traps

• Constitution: Disease, Energy Drain & Poison

• Intelligence: “Arcane” magic, (any magic that did not come from a Divine source)

• Wisdom: “Divine” magic, (any magic that did not come from an Arcane source)

• Charisma: Death, charm and fear