All 1st-party classes are available except the Cavalier, Gunslinger, Brawler, Swashbuckler, Slayer, Vigilante, and the Sleuth Investigator archetype.
Only the unchained versions of Rogue, Ninja, Monk, Barbarian, and Summoner can be used.
All DSP classes, including the Belluspex, are available, as well as the Nightblade, the Unchained Ninja, the Masquerade Reveler Barbarian archetype, and Rite Publishing's Occultist class.
All Fighters must be Myrmidons, all Rogues and Ninjas must be Hidden Blades and/or Eldritch Scoundrels, all Barbarians must be Primal Disciples or Masquerade Revelers, all Monks must be Monks of the Silver Fist, in which case they replace their 12th and 16th level ki powers instead of abundant step and quivering palm and can use style strikes with gauntlets, all Mediums must be Spirit Dancers, all Bloodragers must be Primalists, and all Kineticists must be Gamblers.
Unchained Barbarians still use regular Barbarian rage powers.
Fighters gain the Martial Master archetype for free.
Paladins gain the Warrior of the Holy Light archetype for free, unless the Knight Disciple archetype is used.
Antipaladins gain the Dread Vanguard archetype for free.
Rangers gain the Skirmisher archetype for free, unless the Ambush Hunter archetype is used. Skirmishers gain hunter tricks at 4th level and every 2 levels thereafter.
Soulknifes gains the Gifted Blade archetype for free, unless the War Soul archetype is used.
Skalds use Unchained Barbarian's rage mechanic but regular Barbarian rage powers..
Bloodragers use Unchained Barbarian's rage mechanic, but also still the regular Barbarian's rage powers too.