@tincanofthesea Well, how did the play tests go?

@kraytking
I saw this rule not too long ago and have been considering using it. I know it isn’t exactly what you are looking for, but it may spark some inspiration.

Retreating Air Units: If a territory is attacked and all the ground units are destroyed or it contains no ground units after a minimum of one round of combat, all aircraft may move one space to a friendly territory that is not being attacked this turn.

Overall, I think you could be on to something here. I am just making up some ideas I have here on the fly.
Reinforcements: After 3 rounds of combat any units in adjacent territories that have not been in or will be in combat this turn may move to the territory currently in battle.
Retreat: After 3 rounds of combat, any units in the territory may retreat to an adjacent territory.
Major Offensive: If any combat round has lasted less than 3 rounds, all Armor, Mech, and Air units with remaining movement may move to another territory possibly triggering another combat.

• I would be careful of allowing any multi-attack that would make Mech-Inf and Armor units not worth purchasing.

This house rule adds a Vichy French and Free French rule that is easy to comprehend and implement in any game.

It allows a semi realistic Vichy France to be in game that varies in strength as well as beef up the United Kingdom navy which helps balance it and you really get a feel of the Royal Navy being a formidable force. It is a bit of a downer when Germany turn 1 takes out almost all the United Kingdom ships.
It gives Germany some extra navy units to include a transport which helps get an Afrika Korps in the game that we rarely see in the out of box game. However, these ships are not accessible until turn 2. So, the United Kingdom has a chance to take them out.

This house rule has some play testing, but far from perfected. If you have feedback, questions or concerns let me hear them.

Vichy France and the French Resistance: This rule comes into play the first time an Axis power takes Paris, the capitol of France.

After the player who took Paris ends their turn, do the following:

1. The Territory ‘Southern France’ becomes Vichy (Pro-Axis Neutral), including the units on the territory. Those units do not go into the French Resistance (more later). If the Axis already control Southern France, place one new infantry unit of the controlling power on the territory.

2. The Territories ‘Normandy Bordeaux’, ‘French Indochina’ and ‘New Hebrides’ will stay French. Now called the Free French (Allies). If the Axis have already taken these territories no effect will occur.

3. All French ships are replaced with German Warships and must battle immediately if they share a space with allied warships.

   For balancing purposes, setup is altered slightly. 
   - UK Ships: Sea Zone 91 add One Destroyer, Sea Zone 109 add one Cruiser, Sea Zone 110 add One Destroyer
   - French Ships: Sea Zone 92 add one Destroyer, Sea Zone 93 remove one destroyer and add one transport.
   

4. For the remainder of the French territories still controlled by France must have a die roll to determine their side.

   • If a 1-3 is rolled then they are Free French (Allies)
   • If a 4-6 is rolled then they are Vichy French (Pro-Axis Neutral)
     • For all the territories that become Vichy replace the units with Pro-Axis neutral units and place a Vichy roundel on the territory. Then place the French units that were removed into the French Resistance tray.

The French Resistance: You gain two units into the French resistance tray. In addition to those units, you may have a few French Infantry units from the territories that became Vichy (see above).

• Once per turn, the French Resistance Player you may place one infantry unit from the French Resistance Tray. These units may be placed on any currently owned/liberated/allied controlled French territories or London.
  If Paris is ever Liberated, all French Resistance Units that remain must be immediately placed in Paris.

@kraytking
I saw this rule not too long ago and have been considering using it. I know it isn’t exactly what you are looking for, but it may spark some inspiration.

Retreating Air Units: If a territory is attacked and all the ground units are destroyed or it contains no ground units after a minimum of one round of combat, all aircraft may move one space to a friendly territory that is not being attacked this turn.

Overall, I think you could be on to something here. I am just making up some ideas I have here on the fly.
Reinforcements: After 3 rounds of combat any units in adjacent territories that have not been in or will be in combat this turn may move to the territory currently in battle.
Retreat: After 3 rounds of combat, any units in the territory may retreat to an adjacent territory.
Major Offensive: If any combat round has lasted less than 3 rounds, all Armor, Mech, and Air units with remaining movement may move to another territory possibly triggering another combat.

• I would be careful of allowing any multi-attack that would make Mech-Inf and Armor units not worth purchasing.

@tincanofthesea Well, how did the play tests go?

That is better. I assume the setup is drastically changing?
Just curious, why the need to give each unit AA capabilities?

I would recommend not doing 1/2 ipcs.

Wouldn’t this make the AA gun pointless and aircraft would become so weak. I don’t think anyone would buy aircraft. Even if they were 6 IPC you would be better off buying an armor unit.