Hit Die: d4.
Skill Points at 1st Level: (2 + Int modifier) ×4. Skill Points at Each Additional Level: 2 + Int modifier. The psion’s class skills (and the key ability for each skill) are Concentration* (Con), Craft (Int), Knowledge (all skills, taken individually)* (Int), Profession (Wis), and Psicraft* (Int). In addition, a psion gains access to additional class skills based on his devotion:
All the following are class features of the psion.
Weapon and Armor Proficiency: Psions are proficient with the club, dagger, heavy crossbow, light crossbow, quarterstaff, and shortspear. They are not proficient with any type of armor or shield. Armor does not, however, interfere with the manifestation of powers.
Power Points/Day: A psion’s ability to manifest powers is limited by the power points he has available. His base daily allotment of power points is given on then Psion's class table. In addition, he receives bonus power points per day if he has a high Intelligence score (see Bonus Power Points). His race may also provide bonus power points per day, as may certain feats and items.
Powers Known: A psion begins play knowing three psion powers of your choice. Each time he achieves a new level, he unlocks the knowledge of new powers.
Choose the powers known from the psion power list, or from the list of powers of your chosen devotion/discipline. You cannot choose powers from restricted devotion/discipline lists other than your own discipline list. You can choose powers from devotions/disciplines other than your own if they are not on a restricted devotion/discipline list. (Exception: The feats Expanded Knowledge and Epic Expanded Knowledge do allow a psion to learn powers from the lists of other devotions/disciplines or even other classes.) A psion can manifest any power that has a power point cost equal to or lower than his manifester level.
The number of times a psion can manifest powers in a day is limited only by his daily power points.
A psion simply knows his powers; they are ingrained in his mind. He does not need to prepare them (in the way that some spellcasters prepare their spells), though he must get a good night’s sleep each day to regain all his spent power points.
The Difficulty Class for saving throws against psion powers is 10 + the power’s level + the psion’s Intelligence modifier.
Maximum Power Level Known: A psion begins play with the ability to learn 1st-level powers. As he attains higher levels, a psion may gain the ability to master more complex powers. To learn or manifest a power, a psion must have an Intelligence score of at least 10 + the power’s level.
Devotion/Discipline: Every psion must decide at 1st level which psionic devotion/discipline he will specialize in. Choosing a devotion/discipline provides a psion with access to the class skills associated with that devotion/discipline (see above), as well as the powers restricted to that devotion/discipline. However, choosing a devotion/discipline also means that the psion cannot learn powers that are restricted to other devotions/disciplines. He can’t even use such powers by employing psionic items.
Bonus Feats: A psion gains a bonus feat at 1st level, 5th level, 10th level, 15th level, and 20th level. This feat must be a psionic feat, a metapsionic feat, or a psionic item creation feat. These bonus feats are in addition to the feats that a character of any class gains every three levels. A psion is not limited to psionic feats, metapsionic feats, and psionic item creation feats when choosing these other feats.