For those who want to introduce black-powder firearms into a fantasy world, this is a well-crafted set of notes covering the Shootist character class and general rules for the use of firearms under the Labyrinth Lord ruleset.
The Shootist is treated as the firearms equivalent of a master swordsman, a combatant who focusses on mastery of but a single weapon - in this case the rather tempramental black-powder pistol or rifle (?Rifle... I think they really mean musket, given both the rules and the illustrations).
The claim is made that few people will understand the workings or use of these unreliable devices, which have a base 1 in 20 chance of exploding every time you fire one. At times I'm not quite sure how much the author understands of the workings of these early weapons, at times the text appears to be talking about matchlocks and then a stray cap wanders in. Overall, though, the general flavour is there, although it would be worth taking a moment to survey the early history of firearms and select the point that you wish technology to have reached in your game.
The final illustration shows a 17th century musketeer and, although he's a bit later than the general run of 'mediaeval' style technology prevalent in fantasy worlds, it's probably about the right level if you want firearms to play any meaningful role in your world. To fire one of them, you have to load it with a ball, black powder and wadding, ram this lot home with a ramrod, put a little fine powder in the pan and then ignite that to fire off the main charge within the barrel. Oh, and do remember to take the ramrod out! It's most distracting to fire it across the battlefield, and far less accurate than a musketball. The rules mechanics presented will accommodate this quite well, although it is only the very well-trained musketeer who can reload in a single round especially when in the middle of combat.
Good flavour of early firearms use with perhaps the need for a little informed fine-tuning to make it perfect.