Balancing Modular Gun Crafting

The Internet kind of mucked up the whole concept of experimentation. I know that most of my nephews just look online to figure out the optimal combos, whereas I'm stuck with Nintendo Power magazines for hints. Personally, I love having the capacity to build a range of guns -- some good, some bad -- and enjoy experimenting. The best solution I've seen to ensuring that players have to figure things out for themselves is to have unique randomization for each game session. For example, the effects of each color of magical potion in Pixel Dungeon are randomly assigned each game, although they remain consistent within that game.

The ammo, barrel, stock combo feels kind of arbitrary. Neither the barrel nor the stock house the firing mechanism, for example. Plus, it wouldn't make too much sense for a bullet to be incompatible with a stock, as a shoulder brace is relatively the same for a .22 as for a 7.62. It's easier to refer to it as something like the "body" of the gun. You'd want to substitute "grip" for most pistols, which could be assumed to extend to the trigger action. I also found the scope/sights to be a major decider when selecting a gun in games like Borderlands. Attachments, like a bayonet, grenade launcher, and so forth are also nice. I tend to think of anything other than your factory standard stock as that sort of accessory.

One way to approach things is, instead of bad/awesome guns, give certain combinations additional perks and/or fatal flaws. So, one gun may fire very quickly, but the barrel overheats and either melts down, needs to cool off, or requires a bulky cooling system that impedes movement. There could be a gun that is tremendously powerful but jams constantly. A barrel could accept a certain round but it strips the rifling resulting in steadily worsening accuracy. A gun could seem pretty solid but have a very small chance of misfiring and exploding in the wielder's hand.

What about the feed mechanism and fire mechanism? Do they have variation?

I don't think you should eliminate bad guns. Let players try out absurd stuff (eg .22 calibre will always be a weak round, but maybe it has advantages eg weight and availability). Maybe they'll find a use for it that you didn't even think of that makes a dud good at something.

If you end up with one gun combination that is objectively best in all situations, you've done it wrong. If that happens then anyone who doesn't use that has a disadvantage and that takes all the fun out of having this customisation system. Once people work it out, that information hits the internet and your game dies.

To avoid that, you need to make sure that different choices make a difference to the weapon beside "it's better". If one choice gives a big advantage in damage and no downside then that becomes the outright best choice. But if you have to weigh up advantages and disadvantages of each choice then it's difficult to say there is one objectively best choice.

Just as an example, compare the ammo types 9mm Parabellum and 7.62 NATO. The 7.62 is faster, harder-hitting and has a flatter trajectory. But the ammo is drastically heavier and the recoil is much higher. So if you use 762 you're better off sniping from longer range, you don't have the ammo spare to get into wild firefights and your follow-up shots wont be as accurate if you miss so you want to avoid snap shots. The 762 also requires a longer barrel to be fully effective.

Or you could compare stock types. The easy comparison is stockless vs. solid stock. With stockless the gun will be lighter and easier to move around, so you could ready it and aim it faster. But when it comes to ADS the gun with the stock will be much more steady and absorb recoil much better.

And with barrel types (I assume you mean barrel *length* since your barrel calibre needs to match your ammo calibre or bad things will happen) - the longer the barrel the more accurate and powerful the gun is (up to a point). But again you get a bulkier and heavier weapon that is harder to manoeuvre so readying time would be longer and you wouldn't be able to move it in as well in tight confines.

The disadvantage with a .22 is its relatively low muzzle velocity, resulting in shorter range and less penetration.

The advantages, however, are numerous. The lack of penetration means that the round is unlikely to exit the target when fired at short range, so that it will bounce around inside of the body, potentially causing much more trauma than substantially higher caliber rounds. The problem with rounds like the M855 is that they are made for penetrating body armor, so they'll go straight through an unprotected target without imparting much kinetic energy, hence limited tissue damage and high survivability.

The .22 is quiet and easily suppressed with barely any recoil, which is what makes it so good for target shooting. The ammunition is also very compact and affordable. All of these qualities make it a preferred caliber for professional killers. Although it is unlikely to cause considerable harm at a distance, two to the back of the head will absolutely ruin a person's day.

Even if a .22 leaves proportionally higher amounts of it's energy (ie all of it) in the target compared to a 5.56, it doesn't have a lot of energy to deposit - a 5.56 has more than 10x the muzzle energy. The penetration of the .22 is also so poor that you can't rely on them killing. They can bounce off your skull and your ribs if they hit at a shallow angle. Unless you can guarantee getting a solid hit, you leave the lethality up to chance.

I agree that being quiet is an advantage. But a lot of more powerful pistol calibres can be effectively suppressed too. If your first hit with a .22 fails to kill and the target screams, the suppressor hasn't helped you that much.