Monday, June 1, 2009

Field of Battle: house rules

Warning: The following is specific to Field of Battle rules by Piquet. I make no attempt to put any of this in context for those unfamiliar with the rules.

Over the last couple of years, I have subjected my gaming friends to quite a number of FoB games and a couple of Napoleonic campaigns using the rules for the tactical battles. I estimate I've hosted and/or played at least 150 FoB games. Over this time, we have devised a number of house rules and I thought it would be prudent to put these down in some sort of organized format (with some comments re: motivation/justification). I've noticed that many on the Piquet Yahoo group have come up with similar house rules, which at the very least helps to make me feel less radical. The following house rules are in no particular order. The more controversial among them is included in the Melee section at the end. When I say controversial, I don't mean among our group. In fact, it was one of the easiest rule conversations.

Field of Battle house rules


Skirmish capable units may change to skirmish formation on an even movement roll or a maneuver card (as with any other formation change). In order to change back from skirmish formation, roll the unit's defensive die type v. d8. If d8 roll is higher, the unit may not make the desired formation change.
Note: It's interesting to note that this rule is rarely ever taken advantage of.

Cavalry Opportunity Charges

Any movement within a cavalry unit's frontal 45 degree zone and within 12" may trigger an opportunity charge. The cavalry unit must not be disordered (or routed...duh...obviously!) and must roll it's defensive die v. d8. If the d8 roll is higher, the cavalry unit may not opportunity charge. If successful, move the cavalry unit to contact. If versus cavalry, move both units at the same speed (after the triggering of the opportunity charge) until contact. If versus infantry or artillery, the infantry or artillery unit ceases movement at the moment of opportunity charge triggering and the cavalry unit is moved into contact. When a cavalry unit successfully initiates an opportunity charge against moving enemy cavalry, neither side receives the "up 1" modifier for initiating melee.

Cavalry Opportunity Evasion

Cavalry may attempt to evade any infantry unit (or artillery, though unlikely) moving towards it in the cavalry unit's frontal 45 degree zone and within 12". The cavalry unit must not be disordered and must roll its defensive die v. d8. If the d8 roll is higher, the cavalry unit may not evade. If successful,the cavalry unit may make a retrograde movement at half speed, maintaining its current frontage or may make a full retrograde movement, facing away. Any formed unit or terrain horizon will stop the evasion move.
Note: This came as a response to infantry's ability to move directly to the front of cavalry and loose a volley with no reaction from the cavalry. We have not yet used this rule, so its efficacy has yet to be tested.

Terrain Horizons

Any and all designated terrain horizons require a unit to stop on contact, forfeiting the remainder of its current movement segment. Any remaining movement segments may then be utilized as normal. Exception: Skirmishers are not required to stop on contact with Class II terrain horizons (usually, light woods, fences, small hedges etc).
Note: In our games, any change in terrain counts as a terrain horizon, as do friendly units (which count as Class II terrain horizons). So for example, a formed infantry unit is 5" from a light woods. It receives two movement segments on a Move card. On the first segment, the unit moves to contact with the woods and forfeits the remainder of its movement segment (in this case, 3"). On the second segment, the unit moves as normal in the light woods (i.e. up to 8").

Battle Cavalry

Certain cavalry units are designated as Battle Cavalry and receive an "up 1 die type" modifier in any melee combat. Such units are designated by scenario, campaign, time period, and geographical considerations.
Note: This is lifted directly from Empire. I've never been a fan or proponent of the three typical cavalry classifications, heavy, medium, and light. Of far more importance, I believe, is a unit's capability of being used in the main battle line effectively. Just because a unit is designated heavy or medium does not necessarily make it more effective in combat than a light unit. French dragoons in Spain are a good example of this. While they constituted a French commander's sole "heavy" cavalry contingent, constant campaigning negatively affected not only the men but more importantly the horses. Should a KGL light cavalry unit be inferior in combat to a French dragoon unit merely because of an arguably arbitrary weight classification? Also in the Peninsula, we find Spanish "heavy" cavalry units that by all accounts definitely could not be designated as anything approaching battle cavalry.

Army Morale

In addition to the "down 1 die type" modifier for an army reaching 0 AMPs, the CinC's roll is also modified thus:

25% of units in army routed or destroyed = down 1 die type
50% or more of units in army routed or destroyed = down 2 die types

British Infantry

British infantry (1808-1815, excluding War of 1812) deployed in line formation may immediately initiate melee on an even movement roll and contact with the enemy.
Note: This is an official Brent Oman-sanctioned rule amendment.

Artillery in Melee

If an artillery unit loses a melee by any amount (even if only one pip), it is destroyed.

Artillery Facing Changes

An unlimbered artillery unit may change facing up to 45 degrees only and may never about face 180 degrees.
Note: An artillery unit has a multitude of vehicles and personnel deployed to the rear and making any type of facing change would be incredibly complicated and time-consuming, thus the lesser facing change allowance.

Flank Attacks in Melee

In order to recieve the flanking bonus in melee, the flanking unit must begin its contact movement segment with its center-front behind the target unit's front line.

Cavalry in Woods

Formed cavalry may not enter any type of woods. Skirmish cavalry may move in light woods but at half speed.

Squares & Movement

Infantry squares may move 2" per move segment. Movement must be in the direction of one of the square's facings (i.e. oblique movement is not allowed). A square may wheel up to 45 degrees on a Maneuver card only. Only infantry with a defensive die type of 6 or higher may move in square.
Note: There are numerous examples of infantry moving in square in the Napoleonic period. This rules allows the movement without making the squares into roving pillboxes.


Cavalry v. Infantry in line = infantry down 2 die types
Cavalry v. Infantry in column (2 stand frontage) = infantry down 1 die type
Cavalry v. Infantry in square = infantry up 2 die type; cavalry down 2 die types
Infantry in square v. Infantry not in square = square is "down 2 die types"

When a unit in melee receives "down" modifiers and it is already at d4, any "down" modifiers become "up" modifiers for the opposing unit.

Note: We have also been using another melee convention that, of late, I have begun to question. Rather than using a unit's Offensive die in melee, we have been using the Defensive die types (in melee only). This was initiated originally because of what we saw as some odd melee situations, particularly with cavalry. For example, a 10-4 Prussian Landwher uhlan unit is in melee with a French 12-10 guard cavalry unit. The Landwher initiated the melee so receives the "up 1" modifier. Both receive "up 1" for being in column. The Landwher melee with a d12+1 (d10 up 2) and the French guard are d12+1 as well (d12 up 1). Seemed a little odd. Landwher fighting on an equal footing with guard cavalry? Even if the Landwher started at d8, it would still be d12. A +1 on a die type is really rather negligible. It's not quite the same as a difference in die types. This is also why most in our group rarely use a Tactical Advantage card to give an "up 1" modifier if the die type is already at d12 (better to wait until another opportunity to bump a die type). If we use the defensive die types for the same melee, the Landwher fights with a d8 (d4 up 2) and the guard with a d12 (d10 up 1). This seems more reasonable and allows the Landwher some, but not an equal, chance to beat up on the guard. Now, we have no problem with Landwher occasionally beating up on a guard unit. We recognize that this happened historically and that this is one of the beautiful aspects of the Piquet and FoB system. But these became regular occurrences where clearly superior cavalry were bested by clearly inferior opponents. Occasionally? Yes. Regularly? No. The obvious problem to us with this amendment was that there would be no variations in the defensive die types according to the normal variable unit characteristics. This has not yet been resolved but the use of defensive die types, coupled with the "d4 in melee" rule explained above, seems to give satisfactory results.


  1. Interesting stuff Spqrdave! I have come to similar conclusions and am still experimenting with some modifications of my own -- though most are the same as what you have.
    I really like FoB's ease of play, but I think it does need some modifications to "work right" for Napoleonics.
    And thanks for the link to my review of FoB.

  2. Awesome blog I just discovered today.
    BTW re die type: a UP 1 die type is mathematically the same as a +1 on the result (i.e. average of D6 is 3.5, D8 is 4.5, D10 is 5.5, D12 is 6.5)

  3. Mandarin,

    Thanks for the compliment! You've found one of the many chinks in my wargaming armour...I have no talent with numbers. I consider myself an intuitive gamer, rather than an analytical gamer :)