Below is an outline to make character classes for Dark Sun. It will include a unique and elegant system for psionics for all characters to use.
The system is in between a pure point buy system and the old 3E generic classes. Only these were underpowered versions of the standard fighter, rogue and caster, Athas needs overpowered versions.
Points
The base idea is 4 points per level with which to buy everything, a skill, an ability score point, a proficiency, a save or a feature. As 5E feats are double features, just split them in two. You also have to buy hitpoints. Each point buys your Con modifier in hit point (+1 for a less deadly campaign). You can buy hp twice per level, up to 20 times. A more deadly campaign can have a maximum of once per level, up to 10 times.
The archetype classes below take 2 of the 4 points. Then you have two points left to buy ability score points, features or hp.
You can multiclass these classes, or just swap in a few features of another class.
As a DM, you can change it fully into a point-buy system and use Archetypes as examples. Or, you can make it less freestyle and further restrict options. One point per level could be fixed as Ability Score points and the other can only be hp, skills or picks from a generic feature list. Then, only if you multiclass can you pick class features.
0th level
To create equal progression on all levels, the extra features one usually gets at 1st level are split off into a “0th level”. This is a total of 8 points: 2 saves, 2 skills and 4 remaining points. You can spend them on more skills, proficiencies, or (if you picked Arcane, Religion or Nature as prerequisite) you can pick a type of spellcasting and cantrips.
The proficiency bonus starts at +2 and increases by 1 every 4 levels as usual.
In addition - to lessen the extreme spread in hitpoints over levels - everyone gets their Con score as free hit points.
Dark Sun characters gain a psionic wild talent.
Achetypes
Warrior:
two combat features or fighter class abilities each level. May pick Extra Attack once per 4 levels.
Rogue:
one skill and one rogue feature per level. These are sneak attack (max 1/2 levels, max 5 total) or features like evasion and uncanny dodge. Rogues can pick a skill a second time (expert) to get the proficiency bonus twice.
Caster (Mage or Priest):
Caster level and one class ability (like metamagic).
I’ll detail casters further in a separate post.
New Psionics Concept
Each level Dark Sun characters gain an increasing amount of powerpoints (PP) equivalent to that of a full caster.
Characters acquiring caster levels, can convert these to spell slots. A spell slot level 1 - 5 costs 1, 3, 5, 7 or 9 power points. All remaining PP can be used for psionics, metamagic and 1st level spells.
Gaining 1 point per level per level leads to a nice gradual increase in power (Below is included the resulting number of slots per level).
- You can buy one power per level, each giving one extra psion/manifester level. You can choose to just stay level 1 with just the starting wild talent, pick a few progressing like a psychic warrior or go full psion in addition to your main class.
- Disciplines: telepathy, psychometabolism, clairsentience, psychokinesis, and psychoportation. Maybe one with monk and Soulblade/Mindblade features turned to powers.
- Probably 2 spells per discipline per spell level (max 5, and all unnecessary powers removed)
- No cantrips, and each power is one (or more) spell level higher than an equivalent spell. Remember these are ‘spells’ with build-in Subtle Spell and no material components.
- Psionic powers will use the lowest of two, sometimes three ability scores to manifest.
- Boosting, like metapsionics, is included in the powers. For example, duration could be upped from 1 round/ML to 1 minute/ML to 1 hour/ML by spending 2 or 4 more PP.
Reasoning
First, I don’t want psionics to compete with magic. It shouldn’t be more powerful or there would be no incentive to be a spellcaster. Instead this makes psionics the base from which spellcasters get their magic. Non-caster essentially become psychic warriors and can buy powers to become like full psions.
So psionics does get hit with the nerfbat, but at the same time it’s so easy and flexible it’s close to being overpowered. Powers will be relatively weak, but everyone will have one or more and will get lots of PP fast.
I could and may compile a list of powers, inspired by 2nd and 3rd edition powers or their 5E equivalent, but an easy rule is just compare these to spells cast at one level higher (because of Subtle Spell).
Are the unnecessary flavor wise: scrap it
Is it possibly unbalancing to have at will: modify or add two or three spell levels
Is it nice and comparable to magic: modify and add one or two spell level
PP and spell slots
The standard 5E spell progression would give a wildly fluctuating amount of power over levels, but amount to about the same totals. I recommend this simple and gradual increase of PP converted to this easy spell slot progression:
L PP 1 2 3 4 5
1 1 1 - - - -
2 3 3 - - - -
3 6 3 1 - - -
4 10 4 2 - - -
5 15 4 2 1 - -
6 21 5 2 2 - -
7 28 5 2 2 1 -
8 36 6 2 2 2 -
9 45 6 2 2 2 1
10 55 7 2 2 2 2
You can simply extend this table further up to 18 (171 11 2 2 2 2 2 2 2 2).
Levels 19-24 could be Demi-God/Advanced Being levels like 21-30 in 2nd edition. After this choose to either just give 19 (,20,21…) more PP/1st level spell slots OR any spell slots totalling the level in PP up to 9th (17 PP) OR progress into 10th level and higher slots.