O.1 ROAD-NEGATING TERRRAIN (B3.4; B24.121): Infantry may not claim the extra-MF road bonus during a MPh in which they expend extra MF to derive the protection of shellholes/
O.2 SEWERS & FORTIFIED BUILDINGS (B8.44 & B23.922): A unit may not exit a sewer to enter a Fortified Building Location if it could not enter that Location from outside the sewer. A sewer Location may never be Overstacked.
O.2A TUNNELS & FORTIFIED BUILDINGS (B8.61 & B23.922): Only a unit of the side that constructed a tunnel may use that tunnel to enter a Fortified Building Location and may do so even if that Location is enemy-occupied.
O.2B WALL ADVANTAGE & FORTIFIED BUILDINGS (B9.32 & B23.93): A Gun in a Fortified Building (or Pillbox) Location may never claim Wall Advantage. Its manning Infantry could claim it only by first dropping possession of the Gun. Such a Gun can, however, have a LOS to non-adjacent same-level Locations over the wall hexside(s).
O.3 GULLIES & RUBBLE (B19. & B24.2): A combination gully-rubble hex is a LOS obstacle at both its Crest and Depression levels [EXC: rubbled bridge; B6.331] (deleted by errata). A unit IN such a hex must expend four MF to enter Crest status in that hex (B20.91). A Crest unit in such a hex always receives rubble TEM-not entrenchment benefits. All other Crest rules apply unchanged.
O.3A GULLIES & SHELLHOLES (B19. & B2.4): Shellholes occur only IN a Depression - not at its Crest level. The MF cost to enter a gully shellhole Location is as per B19.4.
EX: A squad IN CC3 may move INTO the BB3 gully-shellhole Location at a cost of two MF, or three MP if also using the shellhole TEM. It may continue movement into AA3 at a cost of two MP (Open Ground) or three MP (if using the shellhole TEM).
O.4 FACTORY MOVEMENT (B23.742): A vehicle that changes its VCA in any Factory Location is subject to Bog. A vehicle that becomes Immobile in a Vehicular-Sized Entrance (5.2; B23.742) does not negate Entrance benefits. Any unit may use the Open Ground entrance benefits of a Vehicular-Sized-Entrance - but only when entering it from outside that Factory and not if that Entrance is Roofless (see 5.42). Such use of OG entrance benefits does not negate that hex's Factory TEM.
O.4A FACTORY TEM/
O.4B FACTORY ROOFTOP ACCESS POINTS (B23.742 & B23.8): Aside from Scaling (B23.424), a Factory Rooftop can be reached from ground level only via a non-rubbled, non-roofless (5.4) Factory Rooftop Access Point; i.e., a printed stairwell or a Location of the Factory that contains a road hexside1. A Factory that contains neither of these Rooftop Access Points must have at least one such Point designated by SSR if its Rooftop is to be usable2. The ground and Rooftop levels of a Factory Rooftop Access Point hex are ADJACENT (see the entry for "Squad K" in the second 5.43 example); intermediate vertical levels do not exist [EXC: for MF-expenditure, LOF and Residual-FP purposes; see O.4C]. Infantry expend two MF (for a 1½-level Factory) or three MF (for a 2½-level Factory) to ascend to the Rooftop or vice-versa.
O.4C ATTACK EFFECTS (B23.8): Infantry changing levels via a Factory Rooftop Access Point may be attacked at ground level (if descending) and/
A unit at rooftop level in a Factory Rooftop Access Point hex being attacked by a same-hex ground-level unit receives the Height Advantage +1 TEM (B23.81), while the ground-level unit receives Factory TEM (and no additional TEM for a Fortified Building Location) if attacked by that Rooftop unit. Both units may use PBF (since they are ADJACENT; A7.21).
O.5 ROOFTOPS (B23.82): A Rooftop Location is Concealment Terrain only for setup purposes. Once the first RPh has been completed B23.82 comes into effect. A Rooftop Location is not considered a building Location for rout and Victory Condition purposes. A Gun may never be Emplaced (C11.2) on a Rooftop.
O.6 RUBBLE & SEWERS (B24.4): Entrance/
O.7 ARMORED CUPOLA (D9.5): Since it is treated as an Immobile tank, CC vs an armored cupola requires the use of PAATC and CCV in the normal manner. An armored cupola set up directly behind a wall/
O.8 ENTRENCHMENTS (B27.): A trench (including an A-T Ditch) may not occupy the same Location as a foxhole.