Classes cover a wide range, from Fighter, Mage and Ranger to Alchemist, Ninja and and Valkyrie, all with unique abilities. Six party members are created, and up to two NPCs can join. Characters also have a Personality trait similar to the speech systems in Sirtech's own Jagged Alliance or in Baldur's Gate, but the player can choose the characters' personalities, and their comments will vary with the Personality chosen. Characters can also be imported from Wizardry 6, Wizardry 7 or Wizardry Gold. Essentially the classic Wizardry system.
Characters gain levels via experience from adventuring and fighting enemies.
Some skills are class-specific, like music for bards and engineering for gadgeteers. NPC's with which you can converse each have their own names, and there are also generic NPCs such as Umpani Guards. Expect one to ten main NPCs per level. Since each group on Dominus has its own goals, NPCs can change their stories, needs and reactions based on previous interactions and events. NPCs have their own Personalities and agendas, and may react badly to some player choices.