D20 Mechanics: Pathfinder Conversions

In the interest of perhaps expanding our potential audience, I've decided that including some "quick and dirty" Pathfinder conversion rules may be helpful.

Overview

Trinity uses a so-called "t20" system, which is a variant of the d20 System per the OGL. When I say "variant," it should be understood to mean that our system is very different from what was born in the early naughts, and attempting to use any of these rules at a table running more-or-less on that engine will result in some... interesting effects, and basically crash your game due to null pointers (no other table, for instance, uses potency).

This page, then, is intended to give you a rough overview of how to "convert" t20 rules into Pathfinder. Because of compatibility, this then theoretically makes t20 backwards-portable to any d20 System game, but - as we all know by now - that's pretty much a lie. I'm sure it can be attempted, but do so at your own risk, and don't be surprised if things get really weird really fast.

Abilities

T20 uses a nine ability score system, rather than the standard six. This can cause some issues as many classes refer to at least one of our three additional ability scores, and some mechanics are dependent upon them.

Perception: References to Perception can be safely converted to references to Wisdom.

Bravery: References to Bravery can be safely converted to references to Charisma.

Luck: References to Luck can be safely converted to references to Charisma. As an addendum, however, t20 uses a heavily-modified variant of action points, and many mechanics refer directly to this resource. t20 assumes 5 action points per game session as a baseline; you can use any variation of this mechanic as you see fit, put it is highly suggested that you allow action points to refresh on a per-session basis rather than per-level.

Classes

All t20 classes have two game mechanic sections, one for t20 and another for Pathfinder.

However, class features are all designed with t20 in mind, and it can be difficult to port these to Pathfinder. We'll paint with a broad brush here.

Proficiencies

Pathfinder armor and weapon lists are significantly more vast than those in t20. Where Pathfinder may have well over a dozen varieties of "sword," Trinity has only three.

Rather than attempt to give conversions for each class independently, use the following guidelines for class groups. In addition, any class that lists a specific weapon - such as axes for berserkers - should gain proficiency with all weapons that could reasonably be considered that weapon type, regardless of that weapon's type in Pathfinder (simple, martial, exotic).

Adepts

Adepts should have proficiency with all simple and martial weapons.

An adept's armor proficiency is based upon their chosen combat style, and they gain the armor proficiencies of the class that corresponds to their choice.

Experts

Giving experts proficiency with all simple weapons is reasonable enough.

Experts should have light armor proficiency, but not with shields.

Sparks

Sparks should have proficiency with all simple weapons. If you feel that's too much, you can instead consider giving sparks the same weapon proficiencies as Pathfinder wizards.

Sparks should have no armor or shield proficiencies.

Warriors

Warriors should have proficiency with all simple and martial weapons.

Warrior classes with a d8 hit die should have light armor proficiency; classes with a d10 hit die can have light and medium armor proficiency; while classes with a d12 hit die should have proficiency with light, medium, and heavy armors.

Defenders and warlords both gain proficiency with shields, but only defenders gain proficiency with tower shields.

Martial Classes and Pathfinder

Some martial classes require some additional attention.

Defender

In t20, defenders gain grit by their armor absorbing damage and by making block checks.

To handle this, I suggest giving defenders DR per the armor as DR rules, based upon the armor they wear, but without reducing their AC.

The Forces and Pathfinder

t20 messes with magic - and other things - in significant ways. This section details how to handle this.

General

t20 shifts the balance for casters from casters setting a DC for a saving throw, to casters making attack rolls with their spells to hit the target. The math is ultimately the same, it just feels better to me to do it this way.

You can easily convert all sparks to Pathfinder by removing references to force attacks of any variety, and instead letting them set saving throw DCs based on the same math, just using "10" in place of "d20."

Magic

Because magic's secondary mechanic interacts with the force attack roll, resonance is instead a range around the mage's saving throw DCs, for which if the target's result is within that range, they suffer the resonance effect.