GURPS Mass Combat: Positional Warfare

Precis: Reducing casualties in GURPS Mass Combat should increase the value of Position Bonus, making for more interesting choices but slowing down battle resolution.

I've been running my GURPS Fantasy Mass Combat game for about six months, and although I generally like GURPS Mass Combat as a quick and simple way to resolve large scale battles and get on to the role-playing, there are some issues.

One that is particularly bothering me is Position Bonus and casualties. Position Bonus (PB) is an abstract value that a force using attack strategies can earn by winning a round of battle. PB improves Strategy rolls on subsequent rounds of battle. Casualties are losses to a force, inflicted in varying amounts to both the winner and loser of a battle round in varying amounts depending on the scope of the victory. Casualties penalize Strategy rolls on subsequent rounds of battle.

The way that the Mass Combat rules read, commanders are supposed to be paying attention to PB, attempting strategies to reduce the enemy PB and striking harder when they have the advantage. In practice, PB increases by 2-3 for a significant victory and by 4 for a decisive victory, while the relative shifts for casualties increase by 2-4 for a significant victory and 8 or more for a decisive victory. In practice, the bonus an attacking force gains from PB is rarely as much as, and often much less than, the bonus the victorious force gets from causing casualties.

It's a bit of a shame that PB doesn't play a larger roll in Mass Combat rules. The following is a house rule that attempts to make casualties less important and PB more important. As a side effect, it should reduce overall casualties for Mass Combat forces to closer to historical norms. More battles should end with a Fighting Withdrawal or Full Retreat after the enemy achieves a sustained (+6 or more) PB bonus, instead of ending when the losing side is wiped out.

Positional Warfare

Resolve the battle as normal on pages 32-38 of Mass Combat. The only change is calculating casualties (p 37). Take the casualty numbers from the Combat Results Table (p 36) and divide them by 5 if the inflicting force used an attack strategy or by 3 otherwise. Round down to the nearest whole number.

Casualties continue to cause a -1 to Basic Strategy Modifier for every full 5% casualties suffered.

Special casualty increases or decreases from battle strategy (winning all-out attack or deliberate defense, fighting a mobile defense or skirmish) are not changed. Nor is the bonus casualties inflicted or save by pursuing a retreating enemy or holding the field.

Example: Using the same base skills and die rolls as the Battle of Drake's Cross from the book, the situation changes. On the first round, Sir Richard's defensive victory inflicts 5% casualties on Strykland's force, while Strykland failed attack only inflicts 2% casualties on Sir Richard.
For the second round, Strykland is still suffering a net -1 skill due to casualties, and will again tie Sir Richard. As both sides are attacking and tied, casualties are minimal, with only 2% inflicted on each side, bringing the total to 7% for Strykland and 4% for Sir Richard.
On the third round, Sir Richard's attack is a win by 10-14. Strykland's loosing defense inflicts another 2% casualties, while Sir Richard's overwhelming attack only inflicts 10% casualties but nets him another +3 in PB.
At the start of the fourth round, Sir Richard is at -1 for casualties and +3 for PB, giving him an effective strategy skill of 15. Strykland is at -3 for casualties and +0 for PB, reducing his effective strategy from 12 to 9. (Though not stated in MC, the numbers for the start of the fourth round would have by -5 casualties, +3 PB for Sir Richard; and -11 casualties for Strykland, or 11 versus a 1). Sir Richard would get another +2 for an all-out attack, while Strykland would have been at a net 0 for a failed Parley (converted into a Defense at -1; Defense normally gives +1 to strategy). An average result on both die rolls would result in a margin 8 victory for Sir Richard. He would gain another +2 PB and inflict another 10% casualties on Strykland's force; Strykland's defense would only inflict 3% casualties (5% on the table, doubled for taking any casualties in all-out attack, and divided by 3 for Strykland's defense strategy).
In the book example, at this point, Strykland's force is supposed to have been wiped out but have actually only taken 80% casualties. Under Positional Warfare, Sir Richard has +5 PB and 9% casualties. Strykland has no PB and has taken 27% casualties. With his position untenable, Strykland attempts a Full Retreat while Sir Richard continues to ride him down with another All-Out Attack. Effective skills are 15 for Strykland and 19 for Sir Richard. Another average set of rolls see Strykland retreating with 0 additional casualties and no more losses for Sir Richard. The good knight now has to decide whether to hold the field (halving his casualties and reducing them by 5% will net him 0 overall for the battle) or pursue Strykland and inflict another 5% casualties for a total of 32% casualties but taking 5% casualties for his own force.

Evaluation

Positional Warfare changes Mass Combat a lot. Battles go on for longer and are more inconclusive: instead of being wiped out in the fourth round, Strykland successfully retreats with  more than two-thirds of his force intact. Attacks are also riskier: a minimal win results in few casualties and little PB gain, while a successful defense by the opponent results in higher casualties for the attacking side for no gain. Both sides have incentive to take Defense strategies, which convert to Skirmish if they both do, making battles even more inconclusive.

Strategically, the fact that most battles are resolved with the losing force retreating in good order, instead of being routed with 50% of the force permanently dead and the rest dispersed, means that the operational/campaign level struggle is also more inconclusive. Losing forces are not destroyed, but instead can retreat and regroup.

Overall, I think Positional Warfare improves Mass Combat, but it does slow at the cost of slowing down play and making battles less decisive. Standard Mass Combat has an advantage that if one force is clearly superior to the other, it can expect to destroy the enemy completely in 3 rounds of combat. Doing so takes a tolerable amount of time in play. Shifting that so that a superior force chases off an inferior force in 6 rounds, only to have to track them down and repeat the process two or three times until they're fully destroyed, might be intolerable in play.

I'd like to experiment more with Positional Warfare, but it's such a style change for my current game that I think the players would hate it. Everyone has gotten used to destroying the enemy in 2-3 rounds and resolving the struggle; switching rules to make combat less decisive would not be popular.