Pseudorealistic Selective-Fire Gunplay for ICRPG: Two Approaches



Being an American, I happen to like guns.* I also really like ICRPG. To date I have not always loved the experience of bringing firearms and gunplay together with my preferred RPG system for a smooth-running and satisfying experience.

Debates about the pros and cons of Master Edition’s addition of the Gun Effort category and associated reordering of the effort dice aside, just as some members here have decided for their tables that parsing melee weapon classes into different categories makes sense for the application of effort mechanics and damage dealing, I understand that the same approach could be applied to firearms.

Our fearless leader has defined “significant math” as one of ICRPG’s core principles; the system is streamlined and easy to intuit because the rules tend to lean toward more meaningful differences and changes within the mechanics of the game, emphasizing a coarse granularity between conceptual categories rather than bogging the system down with countless fine distinctions specific to individual instances within the same broad category of constructs or concepts that, in the end, don’t have a meaningful statistical impact on the results of the action or the in-game narrative.

Just as most ICRPG GMs and players quickly get comfortable with CLOSE, NEAR, and FAR distances on the tabletop, where 25 feet and 30 feet are considered “about the same” for purposes of play, it is proffered in the rules as written that (most) weapons do pretty much the same spread of damage—D6 weapon damage, from a pen knife to a claymore—which means three hits (on average) will (almost) certainly kill a healthy normal person, whether they are incapacitated and bleeding out over the course of a minute or virtually decapitated on the final blow. We all know this is not completely “realistic,” but we are willing to find it sufficiently realistic within the game, owing to the benefits that choice offers us during play. If we adopt such a supplied rule, we never have to look up a basic melee weapon’s damage output in a rulebook, and during character creation we are free to flavor our PCs to fit a preferred theme, concept, or archetype without weighing in-game consequences.

If a collapsible nightstick and a morningstar do the same melee damage, then, by extension, we could agree that a .22 and a .44 magnum handgun both shoot a “bullet”, which puts a “hole” in a target creature for D6 (old rules and many hacks) or D8 damage. By the same reasoning used with melee weapons, I can live with that, even though my knowledge and experience both with firearms and with injury epidemiology inform me that it isn’t particularly “realistic.” It’s a convenient inaccuracy that provides an elegant workable solution.

However, while most melee weapons apply either a “pointy end” or a “smashy end” to a target for the same roughly equivalent effect when viewed in broad strokes, the endless variety and nuance in both early and modern firearms may sometimes prompt GMs and players to find at least some meaningful differences across the very broad range of historical, current, and speculative applications of ballistic technology.

There are two approaches one could consider in creating new pseudorealistic gun mechanics: 1) respecting the power level of the projectiles and 2) respecting the rate of fire.

The first, power level, except at the extremes of the continuum, may be significantly less useful to model accurately in a fast-and-fun tabletop RPG context. While the guys hanging around your local gun shop will debate the underlying minutiae regarding calibers, ballistics, and stopping without end as long as there’s free coffee (and there is nothing wrong with this), common Western service pistol and carry handgun calibers all have relatively similar efficacy (insert grain of salt here) for incapacitation and “ending the fight” by various measures, even though muzzle velocities and muzzle energy vary significantly. People who get shot once or twice tend to die—or at least lie down on the ground and think about dying.

Therefore, for an in-game mechanic where firearms are but one tool in a vast array of roleplay action options available to characters rather than the primary aim (pun intended) of the game, mincing over caliber concerns may not give GMs the best bang for the buck (again, pun intended).

That said, a more meaningful difference within a roleplaying game context like ICRPG that could arguably reintroduce a little more realism is the difference between handgun and long gun (rifle/shotgun) ballistics; generally speaking, projectiles fired from long-barreled (typically two-handed) weapons deal more damage and more grievous injuries than projectiles fired from handguns, so it is reasonable for a GM to put handguns and long guns into different effort categories, with rifles and shotguns using a bigger die than pistols and revolvers. It’s simple, it’s clean, and nobody has to go running to some table to look anything up.

Second, we consider the rate of fire (or, in some cases, the presentation of multiple projectiles by other means). The late 19th and early 20th centuries saw the real-world historical advent and proliferation of first multi-barreled and later fully automatic crew-served battlefield weapons that quickly led to man-portable shoulder-fired automatic small arms for a single combatant (as early as 1885). From an engineering and field deployment perspective, this landmark change brought about a constant technological struggle to balance rate of fire (bullets in the air per minute) with the requirements for cartridge power, effective weapon range, and accuracy. Guns shooting powerful cartridges at very high rates of fire are notoriously difficult to control, but a controllable weapon shooting more moderate cartridges at a reasonable rate can put high percentages of those shots on target within its effective ballistic range. Especially in short bursts, these weapons have a reasonable chance at allowing the shooter multiple hits on a single target with a single quick and efficient aiming action.

The vast majority of RPG encounters involving gunplay (especially in ICRPG) will be well inside the maximum range of most modern cartridges fired from the conventional small arms of both yesterday and today, so again cartridge caliber and power is likely to be a low-yield point of differentiation when it comes to improving realism of selective-fire/full-automatic in game play while preserving the smooth feel of the germane rules during play.

Instead, a more reasonable option to consider is to consider rate of fire, differentiating full-automatic (continuous fire while the trigger is depressed) and selective-fire (multi-round “burst mode” and/or full-auto settings) weapons from slower-rate weapons that fire once per trigger pull (like semi-automatic handguns and rifles, double- and single-action revolvers, lever- and pump-action long guns, etc.). Again we have two good options: 1) assigning full-auto weapons a higher effort die for damage than semi-automatics or 2) treating bursts of projectiles as distinct but related attacks all with the same damage output.

Of course, as originally put forth by our fearless leader, ICRPG made no such distinctions…

“If you are using claws on a monster, it’s a weapon. [Holds up D6] If you are using teeth on a giant biting worm, it’s a weapon. [Holds up D6] If you are using machine guns in a gangster scene, it’s a weapon. [Holds up D6]”

Runehammer (YouTube), “ICRPG: Core Mechanics” (time index 18:00), 23 May 2018

However, with the dawn of the Master Edition, where guns now have their own category of effort and energy/magic effort may be receiving a bump in effort at your table compared to play under Core 2.0 rules, it may worth considering workable revisions to that original streamlining to differentiate with a nod to realism. This is the simple acknowledgment of the fact that, in most cases, while getting shot sucks a lot, getting shot twice sucks more.

The first approach, in line with the spirit of the original mechanics published in ICRPG for simplicity’s sake, is to bump full-auto gun effort up to a larger effort die than the one used for semi-automatics and single-shot firearms. If you’re using D6 for damage dealt by your magnum revolver, perhaps a burst from your Uzi does D8. If you’re assigning D8 for damage to the .380 ACP hit from your superspy’s Walther PPK, a three-round hit of 5.56mm NATO from your marine’s M16A4 might deal D10 instead.

Is changing the effort category and using a bigger die for the damage roll completely realistic? Certainly not. Is it quick, clean, and easy to implement at the table, with neither calculations nor additional steps? Indeed, and it does at least differentiate the game mechanic in the general direction of realism, making it a reasonable compromise. GMs who choose this pseudorealistic hack are prioritizing smooth implementation of the rules at the table, while still balancing the concept of significant and meaningful differences with the added conceptual flavor of more powerful automatic firearms within the game.

Conversely, the second pseudorealistic approach to handling selective-fire multiple-projectile firearms in the game is to keep the damage of each projectile the same but account for multiple projectiles fired as a single game action for full-auto guns.

In the real world, full-auto firearms have a cyclic rate (shots fired per unit time during automatic fire) and an ammunition capacity (the number of rounds carried in the magazine), and so these are translatable with workable accuracy to in-game statistical analogues; in truth, most real cyclic rates are too too high to track during an in-game action turn of several seconds, so as a workaround we might substitute either a burst mode round count (such as 3 for the aforementioned M16 rifle) or a player-allocated number of rounds (with a reasonable cap, such as 10 for a long string fired from a Tommy gun). These two gun stats, capacity and burst round count, work in concert at the table. The M16 firing three-round bursts from a 30-round magazine will go dry after ten game rounds, while the Tommy gun loosing ten rounds each turn from a 20-round stick mag will be empty after two game rounds.

Weapon attacks (like all checks in ICRPG) are made against a target number, either an encounter target level or the Defense (“AC”) stat of a player. This process for determining successful hits remains the same for selective-fire firearms attacks under this alternative mechanic. However, the multiple projectiles fired in a burst are not wholly independent of one another; we do not think of a burst of rounds from a machine gun as projectiles each having their own equal chance of hitting unrelated to the other, but rather a second bullet following the path of the first but potentially disturbed in its aim by the recoil of the round before it, compounded with each subsequent round. Therefore, in an imperfect nod to realism, we can choose to decide that 1) if the first carefully aimed shot in a burst is off the mark, the rest of the burst is likely to miss as well and 2) each subsequent round fired after a successful hit with the first projectile is increasingly less likely to hit. In truth, this is not necessarily strictly true for real-world automatic firearms (cf. “walking in”), but it is a convenient in-game oversimplification that reflects certain realistic trends in likelihood, and it allows us to create an elegant in-game mechanic to model multiple complex real-world factors.

Thus, as an alternative mechanic for full-auto gunplay, a player can choose a target and fire a burst/string of rounds as an action on that player’s turn, respecting the in-game rate of fire and current ammo capacity of the firearm. A single weapon attack roll (DEX) is made (with applicable modifications), and it either falls short of the target number, resulting in a miss for all rounds, or it succeeds, matching the target number or exceeding it by some difference. Matching the target number exactly is treated the same as if only a single shot had been fired; only the first shot hits and the rest either go by harmlessly or cause collateral mayhem at the GM’s discretion, and damage for a single hit is rolled. However, in most cases, the weapon attack DEX roll is likely to beat the target number, and that difference plus one is equal to the number of rounds in the burst/string that hit, up to the number of rounds fired in that turn; this is equivalent to decrementing the attack roll result by 1 on each successive shot. Damage is then rolled for each successful hit, making multiple hits the norm when automatic firearms are in play and making full-auto guns significantly more deadly than under the previously described first mechanic that just bumps the effort category for the multiple-projectile attack.

So, for example, in an encounter with a target of 12, a marine makes an gun attack on an enemy with a modified DEX roll of 13, as she lets loose a burst of three rounds from her M16. With this single roll, we know instantly that two rounds hit (13-12=1; 1+1=2), say for 5 and 3 points respectively, so the enemy suffers 8 hit points of total damage and is badly wounded as one round goes by (GM can determine the effect), the marine’s rifle still holds 27 rounds (down from 30), and the firefight continues. Bloodied but holding on, the enemy combatant decides to empty his Kalashnikov with eight rounds left in bitter retaliation. He rolls a 14 against the marine’s Defense of 14, so she takes one hit as she dives for cover and a string of seven misses zips over her head. Her body armor soaks 2 points of damage from a weapon damage roll of 3, so she gets by with losing only 1 hit point of damage and cracking some ribs from the blunt trauma. As the enemy makes his last stand and goes for a grenade, the marine lines him up for a snap shot and fires another burst of three rounds; this time she rolls a 19, and all three rounds hit for a total of 13 hit points (6, 5, and 2). The tango goes down for good, and the marine can fall back to safety and regroup with her unit.

As an optional modification to this second mechanic, if these high round counts per turn make the damage output under full-auto fire too steep for taste, a gamemaster can reasonably choose to decrement the damage dealt by each successful hit by one point (cumulative) on each subsequent round, reflecting the idea that follow-up shots in the same burst are likely to compound the wounds made by the previous shot(s) rather than compromise new (presumably healthy) locations. (The analysis necessary to determine the truth of such a premise and its magnitude based on real-world data is complex and fraught with obstacles, but there is sufficient potential for logical plausibility that it can be used in-game without necessarily jeopardizing suspension of disbelief.) Thus, the first hit in a three-round burst might do D6 damage, the second D6-1, and the third D6-2; however, there should be a minimum damage of 1 hit point for any successful hit from a firearms projectile. This scales back the awesome power of selective-fire weapons to make full-auto firefights potentially a bit more dramatic, with lots of rounds flying but with opportunities for combatant stamina to still have some effect.

Thus, in an alternate universe, where the tango rolled an 18 to hit the marine above with five of eight shots instead of just one bullet, raw damage of 6, 5, 4, 4, and 1 was rolled for the hits, each decremented by 1 for a modified array of 6, 4, 2, 1, and 1 (minimum). If the GM is being nice, the marine’s body armor soaks 2 points per hit, modified to 4, 2, 0, 0, and 0, so she survives but suffers some pretty bad wounds. Conversely, if the GM is hardcore, the total damage of 14 from the five hits in the burst is only reduced by 2 points by the armor (using the same logic as the damage reduction, that hits in the same location are all compromising the same area—it works both ways!), so the marine loses 12 HP and dies a valiant but tragic death.

Is this second alternative for full-auto gunplay more complex? Certainly so. Does it add more realism? Maybe. I think it employs as few dice rolls and as little math as is feasible in order to integrate some conceptual factors that can still add potential new dimensions to game play by mirrroring the real world.

If I were going to have the occasional assault rifle show up in Alfheim, I probably wouldn’t bother with mechanics like these, but if I were centering a combat-heavy RPG campaign around small-unit skirmishes and ballistic combat using modern firearms, I would definitely consider them.

The two important questions are:

  1. Is it fun?
  2. Is one of these mechanics smooth enough to work at your table?

Only you can decide what works for guns in your game.

This was just my best shot. :wink:

*NB: My opening line was intended to frame my topic with a certain lightness regarding both a cultural issue that can be extremely polarizing in certain spheres and some prevalent stereotypes related to it; mine was a statement of facts about myself that bears no disrespect toward those who are different from me, nor does it in any way make light of the problems of gun violence and warfare we face together as a one species around our planet. Runehammer is a community of creativity and positive interaction, not a political forum, and the contents of this article are offered in good faith within the context of its true aim. Thanks for reading and understanding my intent.

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Wow. That’s a lot. I think you need to check out how Hank and I handled guns in Bearcats and Altered State. Lots of variation there you can modify and adapt to your games to get better gun feel and differentiation between weapons in ICRPG.


Thanks. I’ll check that out. :+1:


I think the general approach is spot on, as far as rate of fire or caliber of round. I am running an ICRPG campaign using modern firearms, and I generally am differentiating based on rate of fire, or caliber of round, and then also mechanical consistency of a weapon (I have guns jam or overheat on low rolls), number of inventory spaces occupied (trade off for the BFGs), range (HARD at FAR or HARD at CLOSE) and then critical hit threshold.

My list was strongly inspired by Ghost Mountain and Altered State.

This is a selection of the guns in my current home brew:

  • SIDEARM. 9mm pistol. GUNS damage, JAMS on natural 1 or 2.

  • MAGNUM. 357 revolver. GUNS damage, CRIT on a natural 19+, Never JAMS. Loud as hell, cannot be silenced.

  • M249 SAW. 5.56mm, light machine gun, ammo belt, bipod attachment. Make 1 attack roll to hit as many targets as you can see. GUNS EFFORT damage. Takes up 2 Inventory Slots. CRITs on an 18+. JAMS on a 2, 3, or 4. On a 1, the barrel overheats for 1d4 rounds.

  • BROWNING M2. .50 BMG, heavy machine gun, ammo belt, tripod or vehicle attachment. Make 1 attack roll to hit as many targets as you can see. 2x GUNS EFFORT damage. Takes 3 inventory slots. Cannot MOVE while using, unless mounted to a vehicle. CRITs on any natural 15+. JAMS on 2, 3 or 4. On a 1, the barrel overheats for 1d4 rounds.

  • AWP. 338 Lapua Magnum, bolt action sniper rifle with telescopic sight, bipod. ULTIMATE EFFORT damage. CRITs on any natural 15+. JAMS on a natural 1. HARD at CLOSE.


Thanks. I appreciate your comments as well as the way in which you have flavored the specific weapons you mentioned (especially the Ma Deuce) through the elegant use of common mechanics.


I am writing up a post apocalyptic hack for ICRPG and have a gun table. Much of it directly inspired by ghost mountain (see that section in master edition for lots more flavor on guns) and altered state. I have leaned into use of HARD/EASY NEAR/FAR, and scarcity of bullets. Guns in my setting are scary and rare, so they are meant to pack a punch.


Love the idea of big guns taking up more space!


Thanks! I’m not totally sure one big item taking up more than one inventory space gels with ICRPG. Not a lot of examples of that in existing ICRPG items, I don’t think. If it becomes too fiddly, we’ll drop it.

But so far my players grokked the idea, and “big-guns-take-more-space” seems like a good trade off to me.

Excited for your apocalyptic hack! It looks awesome!


I find that multiple inventory slots is a great lever to pull on when creating loot. The Iron Shield and the Great Sword take up multiple slots of inventory (2 and 3 slots respectively). You can also go the other way like the Travelers garb and grant extra inventory slots too.


Thank you for posting your thoughts on this- wonderful stuff. I’m from North America as well and I also like guns :slight_smile:

I’ll look more carefully into trying out/testing your alternatives to gun effort, etc. I’ve been working on some World War II-based historical and alternate history scenarios for ICRPG and your posts definitely caught my attention.


I finally downloaded Bearcats today. It’s certainly an innovative and impressive tour de force; it is also quite a righteous homage to its cinematic inspiration, something our fearless leader should be very proud of overall.

Looking specifically at the gun rules to which I was directed, I see that the ballistic mechanics for several classes of more-or-less conventional firearms are included. Examining them as examples one by one, we have…

  • Thumper Pistol: 5 round cap. 1D6 damage single shot, knockback on any hit.—This is your classic large-caliber handgun with limited capacity and plenty of stopping power. Think Dirty Harry’s magnum revolver, something “that’ll blow your head clean off.” It does damage equivalent to a standard WEAPON attack in the ME rules, averaging 3.5 points per hit. Except for its special displacement effect (“knockback”), it’s the same as any single-projectile double-action handgun proposed in the OP.
  • Mac17: D20 rounds fired on hit, 1 damage per round, roll again if nat 20, empty mag on any 40+ burst—This gun represents any number of mayhem-inducing “spray ‘n’ pray” compact full-auto pistol- or carbine-caliber firearms: MAC-10s, Uzi pistols, Nazi MP-40s, M3 grease guns, stocked VP70zs, or (my personal favorite) the oh-so-futuristic P90 PDW. All are high-capacity, high-rate-of-fire, moderate-power, shock-and-awe small arms that excel at close-in fighting. Sending enough lead down range is job #1; maybe they all hit, maybe they don’t… Presumably the effort reduction down to one point of damage per round here is a mechanical reflection of the more moderate muzzle energy of these calibers in combination with the lower hit probability of wild, full-auto fire from short barrels, since mechanically the burst of 1 to 40 rounds either “mostly” hits or completely misses. This makes for an average damage per successful attack of about 11 points with these personal defense weapons, with a decent chance for heavy damage into the 20- to 40-point range—which seems very “swing-y” (as might be appropriate). The mechanics as stated also assume an ample supply of ammo and seem to grant reloading as an implicit free action, only running dry after delivering a maxed-out attack; this might work better for some settings than for others. The Bearcats implementation for this class of firearms seems to have the most different in-game feel from similar guns under the rules I proposed above, where even a long burst with perfect aim from a full-auto weapon (10 rounds is the maximum practical burst size versus unarmored opponents), will deliver just 25 points maximum damage (the chance of this is well under 1%) unless a critical hit is rolled (for 37 points theoretical max), and about 10 points total is the expected average on an unarmored opponent under favorable conditions—still enough to kill the average human with a single attack action, as is appropriate with automatic weapons. Weapon capacity/reloading is respected under my scheme, and so it becomes an aspect of the firearms combat for a different kind of feel.
  • Mag22: 1D4 rounds fired on hit, 1D6 damage per round, mag only empty on a crit fail —This gun is the generic, middle-of-the-road selective-fire small arms weapon, moderate in power, rate of fire, and capacity. Think of certain models of the US Army’s acclaimed M4 carbine (based on Stoner’s AR15) as an example. Bursts of one to four rounds in an intermediate-strength caliber yield appreciable damage per attack (almost 9 points average), and the magazine capacity is ample (with presumed access to spares) but not bottomless under the specified mechanics. This implementation from Bearcats provides very much the same reliable expectation and feel as a similar firearm under my proposal (which would yield better than 8 points average damage per successful attack using three-shot bursts), save for the need to pay attention to the ammo supply and spend actions to reload after running dry.
  • Sniper: 1 mile range, single target, if hit, target must ‘save or die,’ 2 round reload—This entry seems to encompass all manner of scoped “precision rifles”, from a bolt-action deer gun or M24 sniper to a magazine-fed semi-auto like the SVD. Low magazine capacity and unerring long-range accuracy are the hallmarks of the class. Personally, I’m not a big fan of the save-or-die “head-a-splode” mechanic or the play experience it engenders in the game, but it certainly is dramatic. Same thing with range having no effect (although this kind of gun can certainly cover the scale distances on most battle mats with relative ease.) The mechanics of this weapon—while clearly perfect for Bearcats (which explicitly states its intended desire for nail-biting peril and hyperrealistic big-hit energy)—reflect the sort of game feel to which I was offering an alternative when I wrote my OP. While this type of gun was not the principal focus of my proposed rules in the OP (as the title of this thread attests), they still totally work with the same simple mechanics; I would probably just say that these slow-fire rifles with high-powered optics can make called shots EASY at any range, and then grant them extreme-range capability and increased chances for critical damage on those targeted hits—perhaps adding bonuses from both INT and DEX to benefit the cold, calculating long-range marksman with sharp eyes, a steady hand, and nerves of steel. I would also take away these benefits when the shooter isn’t stationary during the turn, since this kind of precision shooting is greatly hampered when on the move.
  • Scatter Gun: Easy to-hit rolls, 30’ range, hits up to 1D6 targets with 1D6 damage each, never empty—While I didn’t give them much lip service in my OP, defensive shotguns (which I adore) are long guns that fire multiple-projectile rounds from a smooth bore all at the same time with the same hit probability; they differ from full-auto single-projectile rifles and deserve their mechanics to reflect this difference. Shotguns deliver lots of effective close-range firepower with diminishing effects at a distance. This gun is a proxy for all manner of pump-action and semi-auto shotguns with low capacity and plenty of kick as their trade-off for maximum close-range firepower and lightning-fast target acquisition. I would probably opt to allow one or two adjacent targets (within CLOSE distance of each other) to be targeted with D8 (or D4 each) projectiles hitting from a single buckshot round fired, with a single attack roll evaluated against each target’s respective DEF score. The EASY to-hit rolls and limited range are realistic and make good sense. “Never empty” assumes infinite ammo (very cinematic!) but works for guns with on-board magazine tubes you can top up on the fly (maybe with a DEX check?). That said, the “alley broom” feel of up to D6 targets “in the zone” is a mechanic that feels very “A-Team” to me (because it’s hard to hit six guys at ten yards with just nine pellets of 00 buckshot…), but I bet it’s fun to play! (See footnote below.)

As I mentioned, Bearcats explicitly declares its own over-the-top action cinema thematic goals (“Statting Guns,” p. 25):

“The guns in BEARCATS are futuristic, so let the[m] be badass! I have my MAC17 firing 1D20 rounds per hit, and natural 20’s exploding for another roll! SO MANY BULLETS. Make your explosives insanely destructive! Work to give every gun its own specific use. They should not overlap.”

The example guns on the list achieve this perfectly; they each have distinctive flavor and weapon-specific mechanics that support them in the game. They seem fun, and they probably work great for the setting and give it an exciting and cohesive feel.

I went with a different approach in the OP because I had different aims and priorities.

First, I wanted to search for workable mechanics that captured sufficient realism without bogging down the game, i.e., no separate to-hit rolls for each round of full-auto fire but reflective of the probability relationships of rounds fired in very quick succession. Magazine capacities were also an important nuance for me to capture, because deciding how many bullets to fire and when to reload were tactical considerations of gunplay I wanted to be sure to include.

Second, rather than defining each and every weapon with a specific set of unique flavoring mechanics, I wanted to define a very short set of universal rules to cover any and all modern firearms and preserve verisimilitude with only a few key gun-specific statistics as input data: firing action, magazine capacity, and effective range.

With these mechanics in place, entries like…

  • Magnum revolver (double-action 1, capacity 6, NEAR)
  • AKM (auto 10, capacity 75, FAR)
  • M4 carbine (burst 3, capacity 30, FAR)
  • M24 (scoped bolt-action 1, capacity 5, EXTREME)
  • Police 870 12ga (scatter pump-action 1, capacity 6, NEAR)

…are all I need—along with a couple of mechanically defined universal weapon tags for flavor (just like melee weapons)—for complete and realistic firearm descriptions, and with a single die roll I know exactly how many rounds hit, how many miss, and how many remain in the gun. The only additional rolls and simple math required are for the damage calculation when multiple rounds hit, and it all makes intuitive sense with respect to the ballistics. (Even these damage calculations could be easily streamlined to a single-roll optional mechanic that still counts rounds, making this style of pseudorealistic full-auto gunplay as fast and smooth as possible, if that is your preference.)

I think all the ideas proffered and referenced by everyone who has posted here have significant merit.

What this exercise has underlined for me is that there is more than one good way to hack this problem. ICRPG presents a bevy of options to handle this type of combat encounter that are easily tailored to support specific styles of play. I think this attribute of built-in support for GM creativity and options during worldbuilding and encounter construction is a clear testament to the brilliant design of the ICRPG system; it is a truly universal gamemaster’s toolkit.

All of you who have had a hand in creating, defining, and refining ICRPG by contributing over the last several years have something to be proud of, and I am grateful to enjoy the benefits of the groundwork you’ve laid.


The accepted rule of thumb among shotgun aficionados, hunters, and LEOs is that standard 9-pellet 00 buckshot fired from the smooth (uncooked) cylinder bore of a typical 18.5” barrel general-purpose pump-action shotgun will exhibit a pattern spread at a rate of approximately 1” per yard of range. Therefore, at ten yards (30 feet, or within NEAR distance), that pattern will place 9 pellets of buckshot in the space of a dinner plate—ten inches across, not ten feet. You might be able to feather that pattern between two bad guys standing right next to each other to hit both with a couple of pellets, but hitting three to six guys dispersed at that range tends to break immersion for me, especially when striving to flavor the mechanics with a little bit of real-world ballistics.


@chrisbynum We’ve got to work on your brevity. lol


Probably. The easiest way for me to do that would be to step away from the keyboard.


I think it is not about typing, it is overthinking. It is great if you are launching a telescope into orbit, but for a game, this looks too much.

By the way, I did read everything you wrote. Overall, I agree with your thinking but I disagree with devoting this much time and energy into what most would call minutia. I am not undervaluing the value of thinking and intelligence and if a game is that important to you, then who are we to judge?

Americans and their guns… :grin:


I’m American, and I don’t like guns in reality, but guns in RPGs are fun!:grinning:

I haven’t read every word written, but I love one line descriptions to sell the difference of one gun from another -it’s great! Keep thinking big thoughts, and including fun things in games! I’m loving all this stuff

Rock on, you crazy gun bunnies!


Honestly, even though it’s a lot, it covers just about every issue and topic that comes up when it comes to figuring out gun play in games. So now instead of sending people a bunch of different links I can point them to this single, all inclusive tome. Sometimes you really need to hit the nail to keep it in the coffin. There might be a better way to sum it up, but this kills a lot of "yeah, but"s on arrival.


Thanks. I hope it’s interesting or helpful to some.


UPDATE: Playtesting of these proposed alternative gunplay mechanics has continued to go quite well at my table in a variety of homebrew one-shots, using the simple one-line clasfication for virtually all firearms (defining action type/rate of fire, ammo capacity, and effective range) in combination with the following global gunplay refinements:

  • The single-roll “damage cascade” technique* for decrementing the GUN effort done on successive hits—so three hits with an effort roll of 6 does 6+5+4=15 total damage—works quite fast to keep the turns moving.
  • I have been using the additional rule for long ranges applied to any weapon that does GUN effort: shots that exceed the weapon’s effective range by one category are HARD, and shots that exceed the effective range by two categories only hit on a natural 20, so a handgun (NEAR effective range) can hit a FAR target on a HARD DEX roll but will only hit a DOUBLE FAR target on an unmodified roll of 20.
  • Magnified weapon optics, AKA “scopes”, eliminate HARD rolls for firearms, so a scoped pistol hits on normal rolls out to FAR range but still requires a natural 20 to hit a DOUBLE FAR target; called shots are still HARD (in contrast to my original suggestion), and the benefits of scopes are lost if the shooter is on the move.
  • Nonmagnified (1x) illuminated “red dot” optics, which CAN be used on the move, make shots within effective range EASY rather than eliminating the extended range penalty (although the shot must be sighted, not a point shot); inventory space permitting, a red dot optic can be combined with a magnifier on any long gun.
  • EXTREME range (anything beyond four bananas) is always at the GM’s discretion, depending upon the configuration of the firearm in question.

Game design geeks with slide rules will note that the damage cascade also makes bursts of full-auto gunfire slightly more “swing-y” in terms of effort by linking the individual hits and making subsequent ones derivative of the first; this means if you roll high damage, all the hits are high, and if you roll low, all the damage is minimal. The original method of rolling and decrementing each hit is probabilistically independent and decremented only by order in the burst, so the base rolls tend toward the the average.


What happens if you roll a 1 or 2 for EFFORT? Would it be: 2/1/0 and 1/0/0? Or would you carry over some 1’s? 2/1/1 1/1/1?


Excellent question. :+1:

Damage effort of 1 is always the net minimum for a successful bullet strike.

Three strikes on an effort roll of 2 becomes 2+1+1=4 points total damage.

Also, I apply GUN effort bonuses to the aggregated total damage of the entire burst, not to each individual bullet strike. (This may seem obvious from a game design perspective, but I put it in writing here anyway.)