'Gonnes. Lots of gonnes.'

Afghan Jezail, 19th century.

When, at the end of the seventeenth century, the French modernes put forward the unprecedented idea that maybe the modern era had actually surpassed the achievements of the Classical world, they held up three examples in particular: the magnetic compass, the printing press, and gunpowder. Guess which one most PCs are going to be most interested in?

Of all the technological innovations of the early modern period, none spread so far or so fast as the use of guns. In remote regions of Russia and Mongolia, still effectively medieval in most respects, guns were enthusiastically adopted by local populations for whom hunting was still an essential part of everyday life. ATWC assumes that guns are ubiquitous: cheap, easy to manufacture, the default weapon for both war and self-defence. However, they exist alongside swords and bows, which they certainly have not yet made obsolete: their slow reload time means that a skilled archer is at least as dangerous on the battlefield as a musketeer, and ensures that a group of swordsman charging at a formation of gunmen only has to endure one or two volleys of fire before they can be up in their faces and cutting them to bits.

All firearms in ATWC are flintlocks. They will not work if they get wet.

Misfires: Early modern firearms were not the most reliable of weapons. If you attack with a gun and roll a 1, the gun has misfired, and you'll need to spend 1d6 rounds (in addition to the normal reloading time) cleaning it out before it's ready to be used again. At the GMs option, characters who are inexperienced in the use of firearms may also suffer misfires on rolls of 2 or 3 until they've had enough practise to get into the habit of cleaning their guns properly.

Rifling: Rifling technology did exist in the early modern period, but most guns were smooth-bore, because rifling made guns more expensive to manufacture and harder to clean. A rifled weapon costs twice as much as a normal gun of its type, and takes 1 extra round to reload (due to the increased cleaning time), but grants a +1 bonus to hit due to improved accuracy.

Spicy-Handed Fists of Death: Yes, you can duel-wield flintlock pistols. Doing so allows you to fire twice in a single round, but imposes a -4 penalty to hit on both shots. And then you have to reload them both. 

Available firearms are as follows:

• Pistol: 1d8 damage, 3 rounds to reload. Pistols are pretty bulky, and in a pinch they can be used as improvised clubs (1d3 damage). Note that it's perfectly in-keeping with history for a character to carry two, four, or even six loaded pistols with them into battle.
• Musket: 1d10 damage, 3 rounds to reload. Two-handed weapon. Muskets aren't all that heavy, but they are bulky, counting as two items for encumbrance purposes. They can be used as clubs (1d4 damage), or fitted with bayonets, which effectively turns them into spears (1d6 damage).
• Carbine: 1d10 damage, 3 rounds to reload. A short-barrelled musket, meant for use on horseback. The short barrel makes them less accurate, imposing a -1 to-hit penalty, but they're much less bulky than muskets and only count as one item for encumbrance purposes.
• Jezail: 1d10 damage, 4 rounds to reload. These long-barrelled muskets were historically popular in central Asia. The extended barrel grants improved accuracy (+1 to hit), but means they take even longer to reload than regular muskets. 
• Blunderbuss: 1d12 damage, 3 rounds to reload. A primitive shotgun: can be loaded with rocks, nails, bits of scrap metal, or whatever other junk you have lying around. Effective range is about fifteen feet, although a generous GM might permit half damage out to thirty.

That covers the basics. But you know what PCs are like: they always want a bigger gun. So:

• Swivel Gun: 2d8 damage, 4 rounds to reload, -1 to hit, ignores 4 points of physical AC. Counts as three items for encumbrance purposes. Too large for a human gunman to use, although a larger-than-human character could use one as a two-handed weapon, and a big enough brass man (strength 15+) could probably just rely on his enormous mass to soak up the recoil. Usually affixed to boats, walls, etc. 
• Small cannon: 2d10 damage, -6 to hit, 5 rounds to reload, ignores 10 points of physical AC. Not very accurate. Not remotely man-portable; usually dragged around by horses or built into the side of a ship or fort. Medium and large cannons do 3d10 and 4d10 damage, respectively. 

Then there are the explosives. PCs love explosives. Actually hitting with a thrown explosive device only requires a to-hit roll vs. AC 10 (plus any modifiers for range, etc, as normal) - after all, you only need the bomb to land in roughly the right area. If you miss, the explosive lands 1d10 feet from the target in a random direction.

The main problem with all early modern explosives is that they have fuses sticking out of them: get the fuse too short and it'll explode in your hand (or in mid-air), but get it too long and your target will just run off, stamp on the fuse, or (worst-case scenario) throw it back at you while waiting for the fuse to burn down. If you're a fighter, assume that your years of military experience have taught you exactly the right length of fuse to use, so that you only need to roll on the hilarious fuse length mistake table on an attack roll of 1. Everyone else has to roll on an attack roll of 1, 2, or 3:

1d4 Roll	Result
1	Fuse much too short. Make a REF roll to realise your mistake and pinch it out before it goes off; otherwise it explodes in your hand for full damage, probably wrecking your hand in the process.
2	Fuse too short. Explodes in mid-air, half-way to the target.
3	Fuse too long. Won't explode until 1 round after impact, giving target time to stamp out the fuse, run off, take cover, etc.
4	Fuse much too long. Won't explode until 2 rounds after impact, giving target time to pick it up and throw it back!

• Black powder grenade: 1d6 damage to everyone within 5' of impact (REF save for half damage). Anyone in heavy armour (half plate or better) takes half damage, as their armour soaks up most of the fragmentation. A bandoleer of six grenades counts as one item for encumbrance purposes.
• Satchel full of gunpowder with a fuse sticking out of it: 2d6 damage to everyone within 10' of impact (REF save for half damage). How far do you reckon you can throw it?
• Barrel full of gunpowder with a fuse sticking out of it: 4d6 damage to everyone within 15' of impact (REF save for half damage). Throwing something this heavy at all requires at least Strength 15. Throwing it more than 15' probably requires Strength 17. 

So there you have it: OSR rules for black-powder weaponry. Have fun blowing yourselves up!