Lets try this for the Cavalry: (Please playtest amongst yourselves and tell me what you think)
A cav unit is considered to be out of supply when it begins a turn more than 4 movement points away from a friendly active rail line.
Cav units that are OOS cannot use column movement. If they begin the turn in enemy territory (as described by the prewar borders)their regular movement is halved.
It cost a cav unit 3 movement points to destroy an enemy rail line. It costs an inf unit 1 movement point.
In winter, cav units have thier movement allowance reduced by 2, and are OOS if they are farther than 3 movement points away from a friendly active rail line.
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I don't remember who posted these house rules, but they have some interesting
ramifications...I've used them but haven't had them come up in play yet. I
also think that I modified the Belgian Effectiveness Rating to match what Dave
Schroeder (the game's designer) suggested in a follow up post.
Here's version 1.1 of my experimental HQ Reserve Rules... Feedback is welcome.
18-21 Infantry, Mountain and Marine units may be placed in defensive reserve. Cavalry units (only) may be placed in offensive reserve.
18-22 For a unit to be placed in reserve, it must end its movement phase in a hex with a friendly HQ of the same nationality. The unit placed in reserve may not have moved during its movement phase, although the HQ may have moved into the hex with the unit.
18-23 To designate which units are in reserve, simply place them below the HQ unit in the stack. Those units not in reserve, are placed above the HQ. (Optional: To simulate fog of war, players may not examine units below the other player's HQs.)
18-24 Each HQ may have 1 XX or its equivalent in defensive reserve, plus 1 cavalry XX or 2 cavalry X in offensive reserve.
18-25 Once a unit is placed in reserve, it may remain in that condition indefinitely provided that it does not move and remains in a hex with a friendly HQ (though not necessarily the same HQ). A unit may leave reserve status simply by moving during its movement phase or being repositioned above a HQ in the stack during the movement phase.
18-26 Units that are in reserve defend normally if the hex in which they are located comes under attack. No die roll is necessary to "activate" them.
18-27 Units in defensive reserve may attempt to "activate" and join a declared battle if the hex in which the battle is taking place is within the MP allowance of the unit in reserve (count terrain and ZOC costs as normal).
18-28 Units in offensive reserve may attempt to "activate" and use "exploitation movement" once a declared battle is resolved so long as the hex in which the combat took place is within the 3 MPs of the unit in reserve (counting terrain costs but ignoring ZOCs).
18-29 When using this experimental rule, each player's combat phase is altered as follows:
1. As each combat is declared by the attacker, the defender declares if he will attempt to commit reserves.
2. For each defensive reserve unit attempting to join the battle, the defender rolls one die and compares it to the HQ Effectiveness Rating of its nationality.
3. If the number is < or = to the HQ Effectiveness Rating, the unit is immediately picked up from its hex and is placed in the hex being attacked.
4. Step 2 is repeated for each defensive reserve unit attempting to join in the combat until the hex being attacked is at maximum stacking (6 divisions + 3 artillery), there are no other reserve units within range of the battle hex, or the defender does not wish to activate any more reserves.
5. If a unit rolls a number > than the HQ Effectiveness Rating of its nationality, it remains in reserve under its HQ and is not committed to the battle.
6. After the defender has finished placing reserves in the battle hex, the attacker resolves combat as normal.
7. After the combat is resolved, the attacker may attempt to commit offensive reserves if all defenders have retreated or been eliminated from the hex of combat. Offensive reserves must be within 3 MPs of the combat hex (counting terrain costs, but ignoring EZOCs). When attempting to commit offensive reserves use the following procedure: a. The attacker rolls one die for each offensive reserve unit he wishes to use and compares it to the HQ Effectiveness Rating of its nationality. If the number is < or = to the HQ Effectiveness Rating, the unit is immediately picked up from its hex and is placed in the hex vacated by the defender. b. The unit may then move an additional 3 MPS as an "exploitation movement" (applying all regular movement costs including EZOCs and terrain). c. If the number rolled is > the HQ Effectiveness Rating, the unit remains in reserve under its HQ. d. Once any and all offensive reserve units have finished their exploitation movement for that battle, the attacker may advance the units that initiated the combat into the hex originally vacated by the defenders, applying the regular advance after combat rules.
8. The attacker proceeds to his next combat if any and the procedure of steps 1-7 are followed.
18-30 Once a combat is declared, the attacker may not abandon the attack because of the arrival of defensive reserves.
18-31 Defensive Reserve units committed to a battle require supply as normal in order to counterattack at full strength.
18-32 National HQ Effectiveness Ratings simulate the general staff capabilities, planning abilities and doctrines of the various countries' armed forces, combined with the concepts of friction and surprise.
1. German HQs = 5
2. British HQs = 5
3. French HQs = 5
4. Serbian HQs = 4 (may not put Montenegrins in reserve)
5. Italian HQs = 4
6. USA HQs = 4
7. Ottoman HQs = 4
8. Belgian HQs = 5
9. Austrian-Hungary HQs = 3
10. Russian HQs < 1918 = 3; during 1918 = 2
11. All other minor power HQs = 2