Here's one of my long-time criticisms about D&D - it really discouraged players from crafting the magic items that were so prevalent in the game, both by making them prevalent (so why bother - you find them just lying around) and by making it so challenging to do. A mage could write scrolls easily enough (though it didn't always work and could be expensive), but to craft anything of worth was so much trouble you were left wondering "Who the hell made all of these +1 daggers?? And then lost them!!"
I didn't ever come up with a good resolution to this. Granted, you didn't want your players finding lots of magical items lying around and THEN make their own, too. That was asking for trouble, since they'd certainly craft those items that would best work to their advantage and make them much more powerful than their level would indicate. But it always seemed like a conundrum to me - a way in which the world just didn't seem properly believable.
One way I did find to try to rectify it was through Alchemy. Potions are usually of limited usefulness in that they don't last very long, their effects usually aren't that potent, they're a hassle to carry around, they're susceptible to various types of combat damage, and of course they're single-use only. They struck me as an amazing opportunity to give the players some control over magic-item creation without knocking the game out of whack.
I didn't get to fully test my theory. I'm pretty sure I used alchemy in two different campaigns, but both were fairly short-lived so I didn't get to really see their effects, more's the pity. The proficiency, however, is a thing of beauty if I say so myself. (You may have noticed that I'm often very impressed with my own work. Yeah, you'll get no argument from me.)
It took me a bit to find time to read the whole thing, and it's not perfect. It's incomplete, for starters - I only detailed about a quarter of the potions I'd designed. But those potions are one of the coolest parts - I designed nineteen different concoctions - all of them new - and included sixteen different poisons (Type A, Type B, etc.). There are detailed descriptions for nine of the potions, a few basic numbers for another half-dozen, and brief comments for all of them that include their effects. So it's entirely playable, just not complete.
Why is Alchemy six pages long, you wonder? Six typwritten pages, single-spaced, in a 10-point font? Well, it takes two pages just for the chart of potions and the tables that I'll describe below. Two pages are taken up by the one-paragraph descriptions I wrote of each potion, such as:
Everwake – this bitter-tasting stimulant is often candied over a small fruit. It must be both boiled and melted during concoction, and burns are likely. It takes thirty minutes to mix, cook, form, and cool a batch, which can make up to 8 doses. When consumed, this mixture fends off sleep, allowing someone to continue to travel, work, guard, or perform other activities without the danger of falling asleep. Each dose lasts for 1d4 + 7 hours. When a dose wears off, the user must make a con check each hour (with a cumulative –1 penalty each hour after the first) or immediately fall asleep. If awakened, a second con check (with penalties) may be made to stay awake for that hour, but the next hour will again require a check. Any dose taken before full rest (8hrs) is obtained is considered a consecutive dose. For each consecutive dose after the second, a system shock roll is required or the user has suffered damage from the lack of sleep and the effects of the mixture. Each failure results in a loss of 1-2 points in all ability scores (with any resulting impact on hit point bonuses, available spells, etc.), plus an additional reduction in maximum HP of 10%. These effects are cumulative with each subsequent consecutive dose if the system shock roll is failed, and the effects last until a full 8 hours of unbroken sleep are received.Again, I didn't finish descriptions for all the potions, only some of them, but you get the idea. Lastly, there are two pages describing how the proficiency actually works. It's a bit cumbersome, but given the power of the proficiency - the ability to actually create magic items (albeit ones of very limited purpose) - I needed to be sure the craft wasn't to be taken lightly. The process is fairly and deliberately cumbersome. Hence those tables I mentioned above. Besides the large one that breaks all the different potions down by level and other factors, there are two primary tables: Scarcity and Danger.
The Scarcity table is used to establish how rare the materials are for a given potion. Assuming a "standard" temperate-clime with access to woods, fields, hills, and streams, the DM uses the table to check the difficulty the player will experience in finding the necessary ingredients. He'll first determine whether or not the necessary components actually exist in the area where the Alchemist is searching, then he'll consult the table to calculate how long the character must search to find them. Eventually, there's a mechanism for the Alchemist to make a roll to figure out whether or not the necessary ingredient even exists where he's looking, so he can choose to abandon the search if appropriate.
The Danger table makes the use of this - again, quite powerful - proficiency a bit of a challenge. There is a chance - based on the level of the player and the complexity of the alchemical formula he's attempting to brew - that the character will suffer harm in the making of the concoction. The simplest potions can cause at most 1d4 damage, but the most powerful one - Witch's Salve, which allows the user to fly - is highly volatile during preparation, and can explode for as much as 6d6 damage! In fact, at 11th Level, the chance of that happening is 40%! It goes down by 5% with each subsequent level. Given that this is a proficiency used primarily by mages, who aren't known for being physically robust, the chances of death are actually quite high with some of these formulas.
Now that I've opened up the creaking tome that holds these 10-15 year-old word documents, I'm inclined to finish off the Alchemy proficiency, fleshing out the remaining potions and possibly adding a few new ones (not that they're needed, really). I still think it's a terrific idea and it seems like it would be worth the effort of finishing. Maybe I'll try to get it published, maybe I'll post it here, or maybe I'll see something shiny and wander off to do other things. You never know. You're welcome to comment here, though, if it's something you'd have an interest in seeing in some form or other.
If I get enough response to Alchemy, I might even have to go back and dig up my non-weapon proficiency for Torture. The last two campaigns I ran were, after all, evil.