Mostly every member of the common races, with the exception of the halflings, is a slave or has been a slave of one of the major powerful factions. The masters use their slaves brutally, and force breeding so as to replace slaves that die. Because of this most are separated at least a few generations from those that might have lived before the world was forever changed. This means that most only know about what was before from stories that have been imperfectly passed down.
Most slaves try not to escape, not because they don’t wish for freedom, but because they have no where to go. Some masters occasionally free slaves, but because of the lack of resources for those freed slaves, most end up dying. Some slaves are taught skills by their masters to fill a particular role, and some are taught by the older members of their race.