All right, here’s what I’ve got so far; some basica, and a Telepathy track. It’s all “beta”; I’d appreciate feedback. I’m especially curious as to whether the Telepathy track seems too complicated to manage, or too powerful.
For now, assume that the absolute fastest progression available is Telepathy 1 at 1st level, Telepathy 2 at 3rd, Telepathy 3 at 5th, Telepathy 4 at 7th, Telepathy 5 at 9th, and Telepathy 6 at 11th.
I’m slightly leaning towards limiting even the best psionicists to one track, or maybe one full track and one or two at level 1-2.
For now, assume that once you fail to activate a power, you can’t use that track (or maybe any psionic powers) for a number of turns.
Psionic powers are activated with a psionic proficiency throw. All characters succeed at using psionic powers on a throw of 10+ (modified by the level of the power) at 1st level. The psionic proficiency throw improves either by two every three levels, two every four levels, or two every six levels, depending on character class. Psionic proficiency throws are modified by the character’s psychic ability score, which is one of Intelligence, Wisdom, or Charisma: for a psychic class, the prime requisite is used; for characters with a psionic talent, use the highest ability score at character creation. (This ability score’s modifier is used even if the ability score is lowered later.)
Wisdom modifiers apply to saving throws against all psionic powers, as with magic.
All telepathy power use requires full concentration, precluding movement and other actions. Once activated, telepathy can be used for as long as concentration is maintained; if concentration is broken, telepathy must be reactivated. Concentration is automatically broken if you are damaged or fail any saving throw. All powers use the same range. If a target makes a saving throw, the power must be re-activated before it can be attempted against the same target again.
Undead, constructs, plants, and other creatures immune to charm, hold, and sleep spells are immune to telepathy (at the Judge’s discretion).
Telepathy 1: Range 60’. The telepath can send thoughts into the mind of one living target. These thoughts can take the form of words or images; in the case of words, the telepath and the target must share a language. A saving throw vs. spells allows the target to consciously block the communication.
The telepath can also make a psychic attack: this requires a psychic attack throw, using the telepath’s psionic proficiency throw; treat the AC of the target as ½ its HD or level (rounded down). At this level, the psychic attack can deal 1d6 damage (modified by the attacker’s psychic ability score), or stun the target for 1 round, rendering them unable to act (saving throw vs. spells negates). Each time a psychic attack is used, the attacker must decide which of the available effects to apply.
Telepathy 2: The telepath can read the surface thoughts of one living target, allowing for two-way communication. The target can block this reading with a successful saving throw vs. spells. This can also be used to e.g. detect lies.
The telepath’s psychic attack can now inflict 2d6 damage, or stun the target for 1d6 rounds.
Telepathy 3: Range 90’. The telepath can concentrate for 1 round to detect and locate minds within range, except for those that make a successful saving throw vs. spells.
The telepath’s psychic attack can now inflict 3d6 damage, or render the target unconscious for 1 turn (saving throw vs. spells negates).
Telepathy 4: The telepath can affect multiple targets, up to HD equal to the telepath’s level (or a single target of any HD). Weakest targets are affected first. The telepath can also probe minds, reading deep thoughts and memories; each specific memory takes 1 round to read, and the target can make another saving throw for each (a successful save ends the probing until telepathy is re-activated).
The telepath’s psychic attacks can also affect multiple targets, as above, and can now inflict 4d6 damage, or render the target unconscious for 1d6 turns.
Telepathy 5: Range 120’. The telepath can use mind control, controlling the reactions, actions, or perceptions of targets. These effects end when the power ends.
The telepath’s psychic attack can now inflict 5d6 damage.
Telepathy 6: The telepath can re-write minds, altering the memories, attitudes, and opinions of targets. Each alteration takes 1 round, and allows a separate save to resist. These effects persist after the power ends.
The telepath’s psychic attack can now inflict 6d6 damage, or burn minds, killing targets who fail a saving throw vs. death.