Can Spyrers use territories like vents and tunnels?
Yes, but remember that Spyrers will only start with one random outlaw territory (per Dead or Alive, FM6) and that they do not work any territories. If a Spyrer gang manages to capture a Vents, Tunnels, or other special territory then they may use the special rules for the respective territory during games if they elect to move their base of operations there.
