For a campaign setting I'm looking at having guns as an option (smooth bore for lower ranges, 1 die of damage, worth using "untrained" because of the higher crit chance, but a feat has to be taken to be able to be a crack shot, full round action to reload).
Is this for PCs or NPCs?
Will you truly have NPCs using guns untrained? I don't think a -4 penalty (I'm assuming 3.x here) will ever make up for a high crit.
In addition, why would PCs ever take a weapon that takes a full action to reload? I've literally never seen a PC in 8 years of running 3.x D&D take a heavy crossbow. Not once. This, in fact, describes pretty well why designing "good gonnes" is so hard in fantasy games.
I suppose limiting a setting to primative cannonry or many of the creative chinese rocket-propelled weapons would work, but that's probably another thread.
I believe those weapons were more commonly used in that period than "hand gonnes". (I vaguely recall reading that it took more than a half hour for a cannon to be reloaded in the Hundred Years' War, but so little non-religious material was written then, one source isn't that great.)
Cannons have a different objective IRL than a fireball, but in the simplified game terms of 3e, 4e, and Pathfinder multiple d6s of damage are multiple d6s of damage. Mechanically, "Fireball" in 3e/pathfinder is an explosion, and there were explosive cannonballs.
IMO, anti-building cannons should never even be fired at PCs. They have next to no chance to hit (unlike a fireball, which always does damage unless you've got Evasion).
I can certainly imagine anti-infantry cannons being very similar to fireballs though.
Considering how guns work in every action movie, I am surprised that people find it ruins the suspension of disbelief. I think it has more to do with Tolkien not using any sort of firearms in Lord of the Rings, followed by the myth that early guns revolutionized warfare overnight (cannons kinda did, though).
Most people have never been shot
or chopped by a sword in real life, creating a myth that having a small but deep hole through several vital organs is deadlier than having a large but somewhat shallower slash being put through you by a sword. They'll
both hurt you bad, and hit points are never realistic, but ... guns have to be realistic whereas swords do not.
You're correct that my use of the world "problem" is more of a value judgment than I intended. However, I do think this is the issue with guns. It's probably true that a human would lose to a bear in melee combat, but that just doesn't have the visceral imagery that modern people associate with a gunshot.
It does to me. Having my face literally ripped off by one swing of a bear's claw means I'll never provoke one. I'd end up on my back, blinded, in one blow. Even if that's not "deadly", being shot in the gut is not necessarily "deadly" immediately.
An encounter in which a mighty hero stabs a bear with a sword until it dies seems to me to be fantastical, entertaining, but not completely implausible.
I think this is because it's possible to dodge a bear, or let armor take the hit. Against a gun, you can't dodge, but most people don't shoot very well at all in a combat situation (I think the figures are less than 25% for cops). "Realistically", a gun might be much less accurate but do very high damage, but that isn't going to work in a balanced game system.
The underlying reality (and one which has shaped history) is that guns are much, much more deadly than arrows or swords.
Is that "reality"? Learning to use a sword might take more time and effort, but I'm not seeing a sword as anything but an efficient killing instrument. Very efficient, if your target isn't in heavy armor. Use an axe or mace if they are.