Ok, I have been thinking a little bit more about autofire. In my previous post on damage, I decided to stick with the “MoS multiplier” that aToW and MW3e used to deal with burst fire. However, after thinking about this some more and looking at how a variety of systems handle automatic fire, I have decided to develop some more specific rules about autofire.
It seems that every system handles autofire a little differently and gun nuts tend to complain bitterly about the way it is handled in most systems. A lot of early systems just made to-hit rolls easier when using burst fire, which isn’t quite right because burst fire actually tends to be quite inaccurate. Concentrated burst-fire is more about stopping power (i.e. putting a bunch of bullets in the other guy rather than one) and “bullet spraying” is more about suppression than an honest attempt to hit anything. The most common technique in most existing systems is to add some kind of damage bonus for burst fire to simulate the stopping power and then to add on some option for suppressive fire. The problem with the first approach is that increasing damage artificially improves armor penetration in most systems because you do more damage on a single attack. Now I am by no means a gun nut. I have never even held a real gun, much less fired one. So most of my knowledge here is about what others have said. That having been said, here are my goals for autofire in MW2.MINE:
- A system that provides players with several tactical options that allow for more interesting gameplay, without adding needless complication.
- A system with a sense of versimiltude without getting into the nitty-gritty details of real-life modern warfare.
- Distinguish a full burst that might be fired at multiple targets or a single target, from a short concentrated (typically three-round) burst mode.
- Integrate double-tap rules into autofire rules.
- Allow for a suppressive fire option.
- Make burst fire powerful, but not an auto-kill in most situations.
Rate of Fire
All fully automatic weapons have a rate of fire (RoF). As a complex action, a fully-automatic weapon can be fired a number of times equal to its RoF in a single round, at multiple targets or a single target. If fired at multiple targets, these targets must be within 2 meters of one another. Each attack expends 3 ammo. Such attacks are more difficult because of the recoil caused by automatic fire. For each attack made, a +1 recoil penalty is applied to all attacks. So, an automatic rifle used to make three attacks in one round would have a +3 penalty applied to all three attacks.
Some fully automatic ballistic weapons can be switched to a three round burst setting as an incidental action. A three-round burst uses up three rounds (duh) but is resolved as a single simple attack action with a +1 recoil penalty. If successful, the player rolls on the cluster hit table in the “three” column. The damage from each successful hit is resolved separately, including damage reduction against armor.
Semi-automatic and automatic weapons can also fire two bullets in rapid succession when the user quickly pulls the trigger. A double tap uses 2 rounds and is resolved as a single simple attack action with a +1 recoil penalty. If successful, the player rolls on the cluster hit table in the “two” column. The damage from each successful hit is resolved separately, including damage reduction against armor.
Fully automatic weapons can be used to lay down suppressive fire. Suppressive fire uses 18 rounds and is a complex action. The shooter chooses a 90 degree cone extending outward from himself. The user makes an attack roll against everyone (including allies) within this cone, extending out to the weapon’s maximum full range and not behind cover, with all the usual modifiers and with an additional +2 recoil penalty and a +2 penalty for the inaccuracy of suppressive fire, for a total +4 penalty. Anyone who would come under attack and is proximate to some form of cover may decide to dive behind this cover to avoid being fired upon, but they give up their next turn as a result. Suppressive fire is considered to be in effect until the firer’s next turn and if anyone else enters the cone or moves within it (including peeking out from cover), they may be attacked again.
Strength Recoil Modifier
Stronger characters are better able to handle the recoil of automatic fire and weaker characters are less able to handle this recoil. To simulate this, whenever any of the above attacks are used, the overalll recoil penalty is modified by an amount equal to 4-STR. If the recoil penalty is reduced below zero, it is treated as zero. Note that this modifier will result in an increase in the recoil penalty for characters with STR scores below four. For example, if a character with STR 3 is firing a three round burst, his overall recoil penalty would be +2 (+1 for the base recoil penalty and +1 for the strength recoil modifier). If a character with STR 6 is making four attacks with a machine gun with an RoF of 4, then his overall recoil modifier is +2 (+4 for the base recoil penalty and -2 for the strength recoil modifier). If this same character were to use a three-round burst, he would suffer no recoil penalty because his strength recoil modifier is bigger than the base recoil penalty.
So three-round bursts and double tap are handled in exactly the same manner. The character makes one attack roll and then rolls on the cluster hit table to determine the number of hits. This is meant to simulate the boardgame rules (RACs in particular). Full bursts, on the other hand, are resolved as a number of separate attacks that can be used against single or multiple targets.
Because each hit is resolved separately in terms of damage, autofire won’t induce an artificial ability to penetrate armor.
How do all these numbers work out? Well, I went ahead and calculated the average number of hits you would expect using each of the modes based on each target number from 2 to 12. Here is what it looks like:
These numbers are worked out assuming a character with STR 4 (so no strength recoil modifiers). The black line represents the expected number of hits when a single shot is fired (which is simply equal to the probability of success for that TN) and serves as a sort of “baseline.” The basic point here is that full automatic fire is only a viable option when the TN is fairly low. By the time you hit TNs of 5 or higher, you are better off using a three-round burst (if your weapon has that mode) and by the time you hit TNs of 7 or higher, you are better off firing single shots if your weapon doesn’t have three-round bursts. Of course, you also have the option to attack multiple targets with full automatic fire.
Overall, three round bursts are superior to single shots (although you deplete ammo faster). This superiority declines as the TN increases, as one would expect. You get similar effects for double-tapping although beyond a TN of 8, double-tapping actually becomes slightly less efficient than a single shot.
Now for higher STR characters, the picture changes a bit. Basically for every additional point of STR beyond 4, fully auto fire becomes a more viable option. Three-round bursts and double-tap also get better at STR5, but since their recoil mod is only +1, additional gains to STR don’t help them any further. Graphically, here is the same graph as before, but this time done separately for characters from STR3 to STR8.
At STR3 (recoil mod -1), none of the autofire options are very practical above TNs of 4 or so. At a +1 mod, the expected hits for a three-round burst and double tap jump up at all TNs, but then stay the same for all other mods (because you have effectively reduced the recoil penalty to 0 and can’t go below this). At each positive level of the recoil mod, full automatic fire becomes a more viable option. At recoil mod 4, there are no recoil penalties at all and the value of each line is simply the probability of hitting at that TN multiplied by the number of shots fired. Of course, STR8 characters are going to be very rare, but even a STR5 or STR6 character can be much more deadly with an automatic weapon.
Here is a full example I worked out, based on these rules and the damage rules from before. I am including armor and hit locations rules that I have not posted yet, but I will post those in the near future.
Musashi, a DEST operative with a STR of 5 and a base Small Arms TN of 2 fires his SMG (AP2/BD6) at Gunther, a Steiner soldier with a BOD of 4 and a WIL of 4 wearing a flak jacket with a ballistic AV of 7. Musashi is kneeling behind partial cover and uses a complex action to make three attacks on Gunther (his SMG has a RoF of 3). Gunther ran this round (+2) and the attack is at medium range (+2). Because Musashi has a STR of 5, his total recoil penalty is +2 (+3 base recoil penalty and -1 for STR of 5). So, the TN for each attack is 8 (2+2[target running)+2[medium range]+2[recoil penalty]). For his first attack, Musashi rolls a 5, so this attack misses. For his second attack, Musashi rolls a 9, so he hits. Since the margin of success here is 1, Musashi applies a total of 7 damage. This damage is adjusted by Gunther’s armor to 2 (7-(7AV-2AP)). Musashi then rolls a 4 on the hit location table, indicating a hit on the right arm. He divides the damage by 2, resulting in exactly one point of damage. Gunther must make a KO check, but he has only one point of damage (Lightly Wounded), so this KO check is made with a -3 mod. Given his BOD and WIL, Gunther’s TN is 3 (Base 6 – 3 mod). He rolls a 7, so he is still conscious. Since the attack did less damage than his BOD, Gunther does not have to make a check for bleeding. For Musashi’s final attack, he rolls an 11. Since his margin of success is 3, he applies 9 damage. This time he rolls a 7 for hit location, indicating he hits Gunther in the Torso. After adjusting the result for Armor, he applies 4 points of damage. Gunther has now suffered 5 points of total damage so he is Moderately Wounded and must make a KO check with a -3 mod. His base TN is 5. Gunther rolls a six, so he just barely stays on his feet. Since the damage is greater than his BOD score, he must also make a BOD check with a -3 mod to see if he is bleeding. The TN for this check is 5, but Gunther rolls a 4. He is now bleeding and will suffer 2 more points of damage at the end of each turn until he gets medical attention. Now it is Gunther’s turn. He wisely hits the deck and calls for a medic.
Armor makes a difference. If Gunther had been unarmored, he would have suffered 13 points of total damage rather than 5. This amount of damage would have made him Critically Wounded and thus his KO and bleeding checks would have been significantly more difficult.