Looking for a good/easy Mass Combat systems
- Thread starter Suldulin
- Start date
Tonguez
A suffusion of yellow
This is the system I use, it works well so far, and is based primarily on what I call the Unit Rating (UR). I have so far worked this at two scales (Units of up to 100 with a Scale of 10 and Units of 100 to 1000 with a scale of 100)
UR = (Unit Size/scale) x HD-1 + Unit Level
this UR is added to the stats of a base creature to determine the Units Stats
Alternatively the UR can be used as a straight modifier to a D20 roll for a 'quickplay' result (highest total wins the battle)
Example 400, Gnoll recruits
Unit GNOLLS
Unit Size 400 (scale/100 = 4)
HP 3600 (400x9)
HD 2 (9)
Unit Level 1
Unit Rating +8 ((Unit scale) x (1+1))
Move 30/20* (*in armour)
Initiative +8 (0+UR)
AC 25 (17+UR) Scalemail, sheild,
Bab 11 (3+UR), 9 ranged
Saves Fort +12, Ref +8, Will +8 {+UR)
FacexFlank 40 x 10 (Unit Formation)
Reach 1 (ie only first rank strikes
Damage 160x40 (Axe 1d8=4), 120x30 (bow 1d6 =3)
Feats: Unit Formation
This Unit attacks and acts otherwise as a single Gnoll
eg to attack roll d20 + BAb + UR = d20+11 - this attack is used to confirm a strike.
NB on a nat 20 Critical I allow another d20 to be rolled and added to the BAb score (and thus the Penetration - see below)
eg d20 + 11 vs AC 22 (hits with a BAb check of 26)
Damage is slightly different and depends on a second 'Penetration roll' and the Average Unit Damage stat.
So after the strike is confirmed you calculate Penetration as BAb (26) minus targets AC (22) = Penetration of 4xreach.
Roll another d20 +Penetration 4x1 eg (rolls 9+4 = 13 (x 5 = 65%)
Damage is thus 160 x 65%** = 104 Damage (or 13 gnolls)
(**NB this can go over 100%)
You could roll damage individually but I don't want to bother and find that Penetration adequately covers the range and possibilitiy of crits etc.
UR = (Unit Size/scale) x HD-1 + Unit Level
this UR is added to the stats of a base creature to determine the Units Stats
Alternatively the UR can be used as a straight modifier to a D20 roll for a 'quickplay' result (highest total wins the battle)
Example 400, Gnoll recruits
Unit GNOLLS
Unit Size 400 (scale/100 = 4)
HP 3600 (400x9)
HD 2 (9)
Unit Level 1
Unit Rating +8 ((Unit scale) x (1+1))
Move 30/20* (*in armour)
Initiative +8 (0+UR)
AC 25 (17+UR) Scalemail, sheild,
Bab 11 (3+UR), 9 ranged
Saves Fort +12, Ref +8, Will +8 {+UR)
FacexFlank 40 x 10 (Unit Formation)
Reach 1 (ie only first rank strikes
Damage 160x40 (Axe 1d8=4), 120x30 (bow 1d6 =3)
Feats: Unit Formation
This Unit attacks and acts otherwise as a single Gnoll
eg to attack roll d20 + BAb + UR = d20+11 - this attack is used to confirm a strike.
NB on a nat 20 Critical I allow another d20 to be rolled and added to the BAb score (and thus the Penetration - see below)
eg d20 + 11 vs AC 22 (hits with a BAb check of 26)
Damage is slightly different and depends on a second 'Penetration roll' and the Average Unit Damage stat.
So after the strike is confirmed you calculate Penetration as BAb (26) minus targets AC (22) = Penetration of 4xreach.
Roll another d20 +Penetration 4x1 eg (rolls 9+4 = 13 (x 5 = 65%)
Damage is thus 160 x 65%** = 104 Damage (or 13 gnolls)
(**NB this can go over 100%)
You could roll damage individually but I don't want to bother and find that Penetration adequately covers the range and possibilitiy of crits etc.
Last edited:
MarauderX
Explorer
Something that a DM did on the fly was to take the average number of attacks and AC for each side and got a computer to generate the massive number of rolls, in the example below 2000 rolls for the first fight alone.
Each difference in average HP added 1 to the AC for that group. From this, each hit on the opposing AC would be a kill despite higher HP, etc. This result would be from one day (8 hours) of battle, and would scale down the losses if an attack lasted less than that. The DM knew which side was most likely to win, but did this to get a rough idea of the number of troops we would have left at the end.
So using 1000 gnomes versus 1000 goblins:
Gnome average HP = 5, AC = 16, no attack bonuses
Goblin average HP = 4, AC = 15, no attack bonuses
HP difference(5-4) =1, add it to the gnome AC so it is 17 to hit.
Making a bunch of rolls to see how many hits, given 1000 attacks for each army in an open field with no protection or other strategies:
Goblins hit 143
Gnomes hit 253
So after a full day of fighting, the gnomes now have 857 troops left, and the goblins 747. The goblins decide to keep attacking for another hour to see if their luck will change:
Goblins hit 101 x 1/8 = 12.625, or 12 (round down)
Gnomes hit 199 x 1/8 = 24.875, or 24
The rolls are made like those above and are scaled back to 1/8 the losses for each side. The discouraged goblins would probably fall back as they think another full day of fighting will only yeild more losses. All of the rolls took only a minute to setup and execute, so all of this could be done in a quick time out (with a computer)
This adds the realism of not knowing who has won until the end of the fight. The players can also add to the events with magic, traps, tricks, whatever to help change the score at the DMs descresion. Also not included are bonuses given for defensible positions, ideal conditions, high ground, weather, etc. so there is a lot of room for change, but this can give you a very quick response to a battle you might not have time to a more detailed outcome to.
Each difference in average HP added 1 to the AC for that group. From this, each hit on the opposing AC would be a kill despite higher HP, etc. This result would be from one day (8 hours) of battle, and would scale down the losses if an attack lasted less than that. The DM knew which side was most likely to win, but did this to get a rough idea of the number of troops we would have left at the end.
So using 1000 gnomes versus 1000 goblins:
Gnome average HP = 5, AC = 16, no attack bonuses
Goblin average HP = 4, AC = 15, no attack bonuses
HP difference(5-4) =1, add it to the gnome AC so it is 17 to hit.
Making a bunch of rolls to see how many hits, given 1000 attacks for each army in an open field with no protection or other strategies:
Goblins hit 143
Gnomes hit 253
So after a full day of fighting, the gnomes now have 857 troops left, and the goblins 747. The goblins decide to keep attacking for another hour to see if their luck will change:
Goblins hit 101 x 1/8 = 12.625, or 12 (round down)
Gnomes hit 199 x 1/8 = 24.875, or 24
The rolls are made like those above and are scaled back to 1/8 the losses for each side. The discouraged goblins would probably fall back as they think another full day of fighting will only yeild more losses. All of the rolls took only a minute to setup and execute, so all of this could be done in a quick time out (with a computer)
This adds the realism of not knowing who has won until the end of the fight. The players can also add to the events with magic, traps, tricks, whatever to help change the score at the DMs descresion. Also not included are bonuses given for defensible positions, ideal conditions, high ground, weather, etc. so there is a lot of room for change, but this can give you a very quick response to a battle you might not have time to a more detailed outcome to.
Corlon
First Post
an easier way to do it, is (unless your characters are extremely powerful, epic, etc. and can effect many many numbers of things) just do the immediate area around them, and decide what happens to the rest, based on stats and a couple rolls. Not very mathmatic, but it speeds up gameplay.
Kevin O'Reilly
First Post
For a quick system check out d20 Slaine. Alos, check out LotR roleplay for a good system that transfers easily to d20.
Note, neither have any real strategy, just quick ways to resolve mass combat battles, rather than mass combat tactics
Note, neither have any real strategy, just quick ways to resolve mass combat battles, rather than mass combat tactics
SylverFlame
First Post
Although I feel that anything as important as a city seige should be scripted (at least as far as winners are concerned) I used a very simple tactic in 2e that let me run a full pitched battle with under five minutes prep.
First, you take the number of combatants on each side. This is your Army's HP. Adjust this if you have any important people present, or really high level/cr critters.
Next, you take the average level for the army. Easy, assume half of the combatants are level one and break down the other 50% by assumed experience. Again, special critters will up this number. This is the Army level and will affect number of attacks and bonuses. Use the fighter table. It just makes sense.
Next, the hard one: AC. I found the best way is to not bother since people die all the time in combat. Otherwise, use an opposed die roll with whatever you are using for attack (likely a d20).
Okay, the fun one. Damage. I just used a good ol'percentile die. Why? Well, when your working with huge armies and stuff, it makes it easier. Your HP is huge, and this makes the numbers on par with a single character.
Finally, mitigating factors. A unit of mages can make a HUGE difference to pitched battle. Just like archers and artillery. So, you give them each their own attack phase, with only one attack. Mages just deal damage as armour doesn't really stop a fireball all that well.
Two other things to keep in mind. If one side has a defensive position, like your city, then they should get a Defence bonus, as well as fun stuff like burning pitch. Treat the pitch like a magical attack. Also, those pesky mages can be taken out with scout units (I treated them like mini-armies).
The thing about a seige is that food is important to. If steady supply lines are maintained (magically or some other way) then don't worry about it. If not, then treat it as an undefendable attack that hits once a day. This damage can be dealt to the army, or population in any way the DM chooses. (an army can confiscate all the food [meaning 0 damage until it runs out], or maybe they suffer as much as the population and take 50% of the hit.)
It's an easy way to do it. It works to. Oh yeah, definitely let the PC's do some fighting against the other army as well. Nothing as boring as a DM rolling dice for five minutes while the PC's have d10 spinning contests. (We've all been there haven't we...)
First, you take the number of combatants on each side. This is your Army's HP. Adjust this if you have any important people present, or really high level/cr critters.
Next, you take the average level for the army. Easy, assume half of the combatants are level one and break down the other 50% by assumed experience. Again, special critters will up this number. This is the Army level and will affect number of attacks and bonuses. Use the fighter table. It just makes sense.
Next, the hard one: AC. I found the best way is to not bother since people die all the time in combat. Otherwise, use an opposed die roll with whatever you are using for attack (likely a d20).
Okay, the fun one. Damage. I just used a good ol'percentile die. Why? Well, when your working with huge armies and stuff, it makes it easier. Your HP is huge, and this makes the numbers on par with a single character.
Finally, mitigating factors. A unit of mages can make a HUGE difference to pitched battle. Just like archers and artillery. So, you give them each their own attack phase, with only one attack. Mages just deal damage as armour doesn't really stop a fireball all that well.
Two other things to keep in mind. If one side has a defensive position, like your city, then they should get a Defence bonus, as well as fun stuff like burning pitch. Treat the pitch like a magical attack. Also, those pesky mages can be taken out with scout units (I treated them like mini-armies).
The thing about a seige is that food is important to. If steady supply lines are maintained (magically or some other way) then don't worry about it. If not, then treat it as an undefendable attack that hits once a day. This damage can be dealt to the army, or population in any way the DM chooses. (an army can confiscate all the food [meaning 0 damage until it runs out], or maybe they suffer as much as the population and take 50% of the hit.)
It's an easy way to do it. It works to. Oh yeah, definitely let the PC's do some fighting against the other army as well. Nothing as boring as a DM rolling dice for five minutes while the PC's have d10 spinning contests. (We've all been there haven't we...)
Last edited:
SylverFlame
First Post
I had a good idea!?! *dances a little* thank-you Corlon.
I really have to get out more often...
I really have to get out more often...
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