How mental defense works for psionics
Mental defense is an ability that every monster with access to psionic powers possesses. It means that a psioniciste does not need to have access to the telepathic discipline in order to activate a mental defense.
The descriptor of mental defense is Mental Armor Class.
Activating the Mental Armor Class counts as immediate action. A psionicist can activate its mental armor class even if unconscious or dying.
Mental Armor Class is determined by rolling 1D20 and adding the psionicist’s intelligence, wisdom and charisma modifier, the proficiency bonus plus, eventually, any modifier given by the use of a specific form of mental defense. Unlike the standard armor class, the mental armor class is not static. A psionicist can modify its mental armor class once per round by paying the Initial Cost and by rerolling the Power Check.
Mental Armor Class = 1D20 + Int mod. + Wis mod. + Cha mod. + Proficiency bonus + Mental Defense mod.
A non-psionicist possesses a primordial form of mental armor class. Such creatures roll the D20 with disadvantage, cannot reroll the result and cannot choose any form of mental defense.
Optional Rule. The first time a non-psionicist suffers a mental attack from a psionic creature, it will be entitled to roll for psionic wild talents.
A psionicist possesses one or more mental defenses among the following:
- Intellect Fortress
- Mental Barrier
- Mind Bar
- Mind Blank
- Thought Shield
- Tower of Iron Will
Mental Attacks vs Mental Defenses modifiers
| Mind Blank | Thought Shield | Mental Barrier | Mind Bar | Intellect Fortress | Tower of Iron Will | |
| Mind Thrust | +5 | -2 | -4 | -4 | -5 | |
| Ego Whip | +5 | 0 | -3 | -4 | -3 | |
| Id Insinuation | -3 | +2 | +4 | -1 | -3 | |
| Psychic Crush | +1 | -3 | -1 | -3 | -4 | |
| Psychic Drain | ||||||
| Psionic Blast | +2 | +3 | 0 | -1 | -2 | |
| Ultrablast |