Made thread that somewhat overlaps with this topic, but also talks about 'weapon styles' with dual wielding, different one handed weapon combinations, agile fencing with one hand and so on:
http://tgdmb.com/viewtopic.php?t=54545& ... sc&start=0
A starting point is "What do my game mechanics measure?", with consideration to how much real world tabletop time you want a combat encounter to take, how many rolls are being made, what decisions does the player think about, and so on.
So you figure out what stats your going to measure, then jot down all of the possible combinations of those stats that seem fair and name the weapon categories. For the Not-Mordheim I've been brewing in my head I decided to measure...
Accuracy: How often you land attacks with this weapon
Damage: How hard the weapon hits when it hits
Parry: How good you are at avoiding attacks when wielding this weapon
Reach: Hit guys from afar, when you out range your opponent you have a parry bonus
There's different 'types' of weapons that are generally good at one of the above stats.
+Accuracy: 'dueling' weapons like jian, katana, rapier
+Damage: 'heavy headed' weapons like the axe, machete, mace
+Parry: bucklers, sais, things you'd stick in your off-hand to deflect your opponent's weapons. Proper arrow stopping shields and turtle formation tower shields fall into an 'other' category of boosting your damage soak and to give bucklers and sais a mechanical distinction from them. I'm familiar with the viking combat videos so in this case I'm sacrificing some 'realism' for the sake of mechanical distinction and abstraction.
+Reach: spears, whips too
So a 1h sword gives you just an accuracy bonus, a 1h axe gives you just a damage bonus. Then you have two handed weapons that give you a bonus in two things like...
+Accuracy +Damage: two handed weapon with a long blade like a greatsword or nagamaki
+Accuracy +Reach: two handed weapon with a long grip and sword-like tip, like a yari
+Damage +Reach: Two handed weapon with a long grip and axe/hammer-like tip, like a pollaxe
++Damage: Two handed weapon with a big killy head like a greataxe or massive scythe so you can have a dark knight running around in grim reaper robes and everyone is scared of how much damage he does.
++Parry: A quarterstaff, from little John on a bridge to Shaolin monks standing at the gate; they're great for turtling against someone trying to pass you. Also gives a bonus lore reason for wizards to carry staffs so they can ward off melee opponents before countering with magic.
++Reach: super long weapon like a pike.
Some combinations I felt weren't well represented by a single two handed weapon, so you'll only get these bonuses from dual wielding:
+Accuracy +Parry: classic sword n' buckler combo
+Damage +Parry: axe n' buckler combo
++Accuracy: twin sword style.
Some of these combinations aren't historically 'realistic' but they fall into a category where there's a more 'realistic' option so your more realistic black knight can have a halberd while your more fantasy one can have a scythe.
So I know what stats I want to measure and what weapons fall into what categories, the hard part is figuring out how to write the rules in a manner that mechanically supports what I want for my game.
