Wednesday, December 4, 2024

Upscaling d20 bullet damage

In a previous post tied bullet damage to the diameter of a round multiplied by the ratio of length to caliber in millimeters. This works fine for bullets which rarely go over 1 inch in diameter, and rarely have a ratio greater than 10:1 (which would max out at 10d12). I randomly mentioned this blog, and that got me pondering how the math would work out. Having looked into NATO Fox Calls for fighter planes, I came to realize that a large amount of weapon specs are available for US Munitions on wikipedia. I'm sure missiles are a bit more complicated than what is presented here, but I thought it would be worth the thought exercise. That being said, one note to mention is that in the previous post, the maximum size was d12 for 1". Most missiles are going to be more than one inch, and the inches should probably be multiplied separately from the ratio, but it seems easier to add the inches to the length ratio and multiply by that number. Both methods are shown here so anyone who wants to use them can use either method

Missile                     Dimensions (ratio) Damage
AIM-7 Sparrow (Fox-1)       ~8x144" (~x18)     d12x26  or d12x144
AIM-9 Sidewinder (Fox-2)    ~5x119" (~x24)     d12x29  or d12x120
AIM-120 AMRAAM (Fox-3)      ~7x144" (~x21)     d12x27  or d12x147
AIM-54 Phoenix (Fox-3)      ~15x154" (~x10)    d12x25  or d12x150
AGM-114 Hellfire (Fox-2)    ~7x64" (~x9)       d12x16  or d12x63
RPG-7 Round (~75x950mm*)    ~3x37" (~x13)      d12x16  or d12x39
AT-4 Round (~84x245mm*)     ~3x9" (~x3)        d12x6   or d12x9
Minuteman ICBM (~5.5x60 ft) ~5x60' (x11)       d12x785 or d12x46,800

Percentile Damage
You may have noticed that multiplying caliber and length separately produces damage in excess of 100 in all cases. It may be helpful to roll fewer dice and get bigger damage values. In that case, round the maximum damage to 100 points in whichever direction makes the most sense, and use that number of d100s. The following is the result of that.

Missile                     Damage Maximums    Percentile Roll
AIM-7 Sparrow (Fox-1)       1728               18d%
AIM-9 Sidewinder (Fox-2)    1440               14d% 
AIM-120 AMRAAM (Fox-3)      1764               18d%
AIM-54 Phoenix (Fox-3)      1800               18d%
AGM-114 Hellfire (Fox-2)    756                8d%
RPG-7 Round (~75x950mm*)    468                4d%
AT-4 Round (~84x245mm*)     108                1d%
Minuteman ICBM (~5.5x60 ft) 561,600            d%x5616**

Wednesday, July 10, 2024

I'M BACK! (with) Pathfinder Remaster Musings on Vehicles

 So according to the Pathfinder Remaster, 

Vehicles have size traits, but they don’t occupy the same spaces that most creatures use. Instead, each vehicle has specific dimensions provided in its stat block.

Most vehicles are Large or larger, and many vehicles are made for the purpose of carrying cargo. Unless stated otherwise, the amount of cargo a vehicle can carry depends on its size, terrain, and propulsion. A draft horse or similar creature can usually pull around 100 Bulk of goods consistently throughout the day, so pulled vehicles can typically hold 100 Bulk per Large creature pulling. Water vehicles, such as ships, have limits that are more based on volume than weight; a ship can hold upwards of 1,000 Bulk. Flying vehicles can typically hold only 1/10 the Bulk of a water vehicle and still remain airborne. The GM might rule that unique or unusual vehicles can hold different amounts of Bulk.

This presents a problem in that vehicles don't usually have large creatures pulling, pushing, rowing or otherwise moving them. This can still be used as a guideline. So for example, a Carriage is 10x10x7 and a Cart is 5x10x4, one is pulled by 1 Large creature the other by 2, so 100 and 200 bulk. These numbers are applied to either (2x2x1.5)=6 five foot cubes or (1x2x.8)=1.6 five foot cubes, though you can also just take the dimensions and divide by 125. Given that, values of 30 to 50 Bulk per 5 foot cube.

What actually is Bulk?

The book says 10 lbs but it also says a medium creature is 6 bulk, which suggests more like 20 to 30 lbs (20 would make medium creatures 120 lbs, and 30 would make them 180). It also says a large creature is 12 Bulk. (which is anywhere from the canon 120 to my recalulated 360). To be clear, bulk should be a range based on a nebulous combination of length and weight, not just one particular weight or one particular length.

My initial "gut reaction" of 25 bulk per 5 foot square is reasonable when taken in consideration for the fact that vehicles' own Bulk isn't considered for its weight limit, but I'm inclined to consider the following

  1. (50xCubes)-(Bulk of Creature listed in Player Core p. 269) Bulk for the same size creature (500 to 1500 lbs per cube)
  2. 25 to 30 bulk per cube ignoring the "Bulk of a Creature" appropriate to a vehicle of the creature size (250-900 lbs per cube)
  3. Water vehicles basing their cargo on volume rather than weight still hold 10x the volume of land vehicles calculated this way (e.g. one of the above calculations).
By the rule quoted above Flying vehicles at 1/10th the capacity of a ship (or equal in capacity to a Land Vehicle) can remain airborne. I don't have a particularly strong opinion on the validity of that assessment.

Tuesday, January 5, 2021

Musings on Firearms in d20

A long time ago, way back before there were two kinds of Dungeons and Dragons, in an era where the first kind had only three editions, there was a modern version, with guns. It was sort of ok for generic purposes, but they ended up having to put out further supplements on additional firearms, both fact and fiction. That's all well and good, but ya know... it's probably out of print or something, and also you might not want to encourage piracy even if there aren't going to be particularly strong consequences for it. With that in mind, I came up with my own system for gun damage.

Damage Dice
Guns (and everything) deal(s) damage based on F=MV, but we don't need to complicate this. We can replace F with Damage, M with the size of the bullet, and V with a typical load of propellant. We don't have to even do it directly, we can just sort of provide a logical basis.

In this case, the M of the bullet is tied to its caliber, we'll assume that the following is true:

Caliber     mm           Dice
up to.25    up to 6mm    d4s
.26-.40     7-10mm       d6s
.41-.55     11-14mm      d8s
.56-.75     15-19mm      d10s
.76-1"      20-25.4mm    d12s

The V of the bullet is tied to its case length inasmuch as the case length defines what safe amounts of powder can be used to fire projectiles from it (actually thickness and material is more important than actual length, but it's a close enough abstraction for our purposes). To determine the number of dice, use (Case Length/Caliber in mm, rounding to the nearest whole ratio e.g. 9x19 Parabellum is 2d6 with 19 being 2.1x the length of its 9mm caliber. AK rounds (7.62x39) deal 5d6, and 5.56 NATO rounds deal 8d4. A .50 BMG being 12.7x99 makes it 8d8.  Likewise, a slug in 12 gauge is typically 18.5x70mm, which amounts to a ratio of 3.75, or 4d10.


Shotgun Shells
Instead of going into excruciating detail about how many different levels of buckshot and birdshot there are, we can just assume that buckshot reduces dice size by 1, but adds a 2 dice (5d8 instead of 4d10 for 12 gauge) birdshot reduces dice size by 2, but adds 3 dice (7d6 instead of 4d10 for 12 gauge), and Frangible reduces dice size by 3, but adds 4 dice (8d4 instead of 4d10 for 12 gauge).

Oh and one final thought: That original document may have propagated a myth that shotguns fire in a cone. They sort of do, but even at 150 feet you're only going to get about a 3" spread or so.

Weapon Actions
We will categorize weapon actions more broadly here for the sake of game rules--and because if we didn't a character with an M-16 can easily fire off their entire magazine in under a full round.

Single Shot
Covers breach action shotguns, flare guns, bolt action rifles, and single action revolvers.
  • Each attack with this requires a single action (in PF2e) to bring a new round into battery
Semi-auto
Covers magazine fed auto-loader pistols, double action revolvers, lever action rifles, and pump action shotguns. 
  • You can fire off as many shots as you can pull the trigger. It's a two action activity to multiply damage by 1d3, and a three action activity to multiply damage by 1d6. This costs 3 and 6 ammo respectively
Full-auto
Covers anything where one press of the trigger equals multiple bullets, including modified trigger assemblies that fire a second round when the trigger is released.
  • With selector fire you may treat the weapon as a semi-auto
  • If it's full auto only--or you've selected burst or full auto--you can still limit your trigger pulls to multiply damage by 1d6 with a single action activity (costing 6 ammo)
  • You can multiply damage by 2d6 as a 3 action activity.(costing 12 ammo)

Monday, November 16, 2020

B-Roll Call!

I have released a new game about making B movies! It was originally inspired by one called It Came From the Late, Late, Late Show, but somewhat considerably expands on it, adds rules to things that were discussed in vague terms, and completely reworks most of the base architecture of that game. it can be found here!

Tuesday, March 3, 2020

Dragging a body in d20

Never thought I'd do a rule for d20, but Pathfinder 2 has taken an identity stance I can respect so I'm willing to look into it a little deeper. So I'm reading the bulk section of Pathfinder Second Edition, and I noticed:

1000 coins is 1 bulk and 1 bulk is 5-10 lbs. This was confusing to me because of previous editions being 50 coins per pound, a bulk should be 20 pounds. Also with a medium sized creature being 6 bulk, that's only 60 lbs. at 10 per bulk. I noticed that making Medium Creatures bulk 8-10 keeping small creatures at 2-3, and having 1 bulk correspond to 20 lbs fixes all of these issues for medium and small creatures. Likewise, a large creature could be 12-15 Bulk (240-300 lbs), a huge creature 25-30 bulk, and so on. This does not obey the square cube law but it fits closer to what actual d20 creatures seem to want to weigh, so it works.

Also, side note: There is some text about how an object's bulk is somewhat affected by its awkwardness more than its actual weight, and generally I'm willing to concede the point that a longsword is only a couple pounds, and other such concessions and not change how the rule works overall unless something glaringly annoying comes up. 

Saturday, May 5, 2018

Damage is a Fickle Bitch

The chief complaint I get from my players about DW is that players roll 10 or 12, and get a damage roll of 1 (or sometimes 2-3 if they took the extra d6) and that damage tends to gets soaked by armor. On Reddit someone even told me that late game DW tends to turn into a bit of a survival horror. I haven't tested late game myself, but I can tell you how incredibly frustrating it is that people who are supposed to be capable combatants but roll a series of very low damage rolls can't always take it on the chin like a champ. It is with that in mind, that I randomly thought about making damage less fickle :

Typically a character's base dice will be a d6, d8, or a d10 (with one notable instance of a d12). In order to make damage less fickle, assume one of the following

  • Subtract 4 from everyone's dice type, and add the remainder to a d4. For example, a d10 would be 1d4+6, and a d6 would be a d4+2
  • Subtract 6 from everyone's dice type and add the remainder to a d6. For example, a d10 would be 1d6+4, and a d6 would stay a d6.
Whichever option above is chosen, only modify the base dice. Additional dice granted for any reason remain unchanged.

Thursday, May 3, 2018

On Killing (Not by David Grossman)

In Dungeon World, the price of a typical murder is apparently 5 coins, and the price of a higher profile assassination is 120 coins. This seems awfully low. Given the price of "A Hearty Meal for 1" of 1 coin, I evaluated a coin to be roughly equivalent to 5 USD (given that McDonalds had as of the time writing this a 2/$4 deal where you could get two double cheeseburgers). This means a murder is 25 bucks and a higher profile assassination is 600. This is fitting with the standard DW status quo that prices are low, but also suggests that life is cheap. It also doesn't account for the mark's threat level. These factors should be considered when evaluating the price of an assassination:
  • The number of moves a target has that can be harmful to the assailant.
  • The maximum damage a target can bring to bear. This doesn't refer to the damage the target itself can deal, if it can order others to fight for it.
  • The HP of the target. or the highest HP of  its body guards. (3 minimum)
  • The Armor of the target or the highest among its body guards

For example, a Noble doesn't have any listed attacks, or HP, but they can issue orders and offer rewards to anyone beneath them (2 moves). Often, this is a Knight. which can bring to bear 10 damage, has 12 HP, and 4 armor. Therefore a Noble would be worth 2*10*12*4=960 coins. A King who has  A Whole Damn Army would use 2*19*30*4 would be worth 4560. A mere bandit has 3 threatening moves, can do 6 damage, and has 3 HP, which is 3*6*3  or 54 coins.

If you don't like these you can round to the first significant figure to get a price in tens, hundreds, or thousands. The above prices would become 1000, 5000, or 50. For the purposes of abstract coins, a significant figure 50 to 100 coins is A Chest of Riches, anything over 3 such Chests is a Giant Sack of Loot. 3 of those is "A Small Hoard" which increases the Resource statistic that armies use.

P.S.- It is noteworthy that just because you want someone killed, doesn't mean you're going to get it done by hiring some rando off the street. If you pay 120 coins to them (or 5, or 50, or 1000, or 5000, etc), they might go kill your guy, or they might pocket the money, go brag, and end up on a pike outside the city walls.