Ok...1)obviously lag of at least two rounds is nessecary for this skill, or would be over powered big time. Mabey 1.5 for elves as they are very proficient.
2) Would have to be in scan sight. Two room maximum range.
3) If target is two rooms south, and you intend to shoot them from that location, and in the midst of you typing out the command they move one room closer to you, shot always misses.
4) Whether arrow hits or misses, target is informed of arrows being shot at them and from what direction they are comming at. Perhaps with a message something like *An arrow comes flying from the north and lodges itself in a nearby tree* Depending on the environment you are in.
5) Must collect arrows of course. Must have quiver, and must be wearing quiver around torso or waist to use arrows.
6) All races must buy arrows, with the exception of elven races, which have natural ability to fashion them when in forested area. Or perhaps give them a gather wood skill and allow them to carry wood wherever they please, perhaps to their guild. But put a time limit on this. Perhaps 2-3 game hours before a certain amount of arrows are made.
7) Mabey invokers are capable of wielding small, weak bows, but enchanting the arrows with certain effects. Fire, cold, lightning, acidic. whatever, thats debatable. Certain other classes mabey can learn to just put flaming tips or weak poison on them.
Mabey with mastered archery skill, chance to hit at one room distance is 70%, two room is 50%, increased of course for elves.
9) Elves however, trying to maintain balance, cannot wield large, bows, with high tension and power. Only medium and low tension bows, due to their lack of strength, where as minos could wield massive bows with huge amounts of tension.
10) Perhaps it could be given to only Knights, rangers, fighters, outcasts, mabey invokers, mabey how you decide, make it elven racial skill, including elves, wild elves, and even dark elves. Mabey half elves, as some of them do grow up in silvanesti or qualinesti.
Now, on another note. Thieves and assassins, as opposed to getting archery, could possibly receive a blowgun skill. Same basic idea, just minimal damage, if any, but perhaps with certain venoms and poisons and potions on the tip. Perhaps one could be a sleep dart...mabey overpowered, just a thought. One could be a poisoned dart. One could mabey cause a drowsy effect, something like slow.
This is just a rough sketch of ideas. let me know what you think. If you want to go real in depth with it all, you could easily incorperate some manuals with this, like ability to create a specific poison that is certain death unless cured by healing sleep. Or a poison that incorperates a paralysis venom...again, just thoughts. Let me know Habbakuk.