AT-AT House Rules

• AT-AT Driver (from FU) gains the ability AT-AT Driver - if within 6 squares of the AT-AT the AT-AT may spend a move action to move 1 square backwards or sideways.
• AT-AT gains Massive (like the DDM Colossal Red Dragon) - ignores walls when moving, can end it's move in a wall.
• DR20 save 11, on a failed save it only has DR10.
• Save vs. STOMP is made BEFORE entering the square of a character with the EMPLACEMENT Special Ability.

Windows

• Windows can only be destroyed using Satchel charge
• Characters adjacent to a window can shoot 'out' of the window.
• Line of Sight can be drawn to adjacent characters behind a window, but the window does provide cover.
• If both characters are adjacent with a window between them they both receive cover, including characters with Melee.

Grapple/force back

• Only adjacent characters may Grapple.
• Grapple may only be performed on a characters own turn.
• Grapple 'Replaces Attacks'
• Characters with 'Damage 0' may Grapple.
• An Attack roll is required for a Grapple.
• If the Attack roll hits the target is moved one square to an adjacent vacant space (so cannot be forced onto cover or rough terrain or diagonally)
• This movement does not provoke an Attack of Opportunity.
• The target may be moved into a pit but gets to make a Save 11.  If this save fails the target is defeated.  Characters that 'Avoid Defeat' by any means remain on their original space.
• Only characters of equal base size or smaller may be Grappled.

I considered not allowing characters with Flight to be Grappled into a pit, but hey, that's how Boba Fett is defeated in Return of the Jedi.