Hinterlands is a simple set of skirmish rules that uses Age of Sigmar as a base, and adds elements from Necromunda or Mordheim. The rules are actively developed and as AoS28 evolves we’ll see community feedback and playtesting influence the new editions.
Although there are lots of other rule sets you could use for AoS28, Hinterlands is a great way to use your models in narrative games without learning any new rules or investing in a new system.