When I first returned to D&D through the 3.5 edition rules, I was quite impressed by the idea of attacks of opportunity, though as a game mechanic they add a lot of work and could perhaps be simplified without difficulty. I particularly liked their use to discourage spell-casting and missile weapon use in melee combat, encouraging the eminently sensible tactic of keeping archers and wizards behind a wall of warriors, and reducing the use of healing magic in the thick of battle. I think they can be used as well to address that old canard of D&D, the uselessness of pole-arms, quarterstaves and great axes. No-one in D&D would ever actually bother specialising in pole-arms as a weapon because they’re heavy, they do less damage than comparable two handed weapons, and yet you still have to forego the use of a shield. Even worse is the quarterstaff, which is weak and requires you forego the shield bonus. Sure, you can set a pole-arm against a charge, but how often do you have to do that?

Over at Middenmurk I found a suggestion for improving the pole-arm based on initiative order, which is nice but I don’t think is sufficient to overcome their deficiencies. This post reminded me of an idea I have toyed with for a while, which can be implemented in pretty much any system (I think), and uses attacks of opportunity to make pole-arms and spears a fearsome weapon, to improve the value of daggers for dexterous fighters, and to make the quarterstaff a useful weapon, particularly for mages. Here is how it works:

  • In any combat where the combatants start at greater than melee range, L-sized puncturing weapons (i.e. pole-arms and spears but not two-handed swords or battle-axes) win initiative, so always strike first, against any other weapon class
  • Any M or S-sized weapon user fighting against an L-sized weapon of any sort[1] incurs an attack of opportunity when they attempt to strike
  • In order to prevent this attack of opportunity from occurring, the user of the smaller weapon has to exchange their attack for a combat manoeuvre roll, which if successful indicates they have closed range sufficiently to be able to attack subsequently without incurring the attack of opportunity. Failure, of course, means that they incur the attack of opportunity as well as losing their own strike
  • Once the user has closed successfully in this way, the pole-arm wielder can reverse the procedure, dropping their own strike and making a combat manoeuvre roll to widen the range again without incurring an attack of opportunity
  • If a person using an S-sized weapon closes successfully against a user of an L-sized weapon using this method, they’re considered to be inside the range of the big weapon, and then the big weapon user incurs an attack of opportunity every round that they attempt to strike the lighter fighter, until they widen the range again[2]
  • A quarterstaff can be used as a pole-arm at range (the Chinese kung-fu-y style of staff fighting) but can also be treated as an M-sized weapon (the Robin-Hood style of fighting) so quarterstaff users get the benefit of the pole-arm without its deficiencies against light weapons
  • Users of S-sized weapons do not gain the attack of opportunity advantage when fighting against Great Axes, but do suffer the attack of opportunity disadvantage when fighting at range against Great Axes
  • All combatants have to make their decision about what they’ll do at the beginning of the round, before initiative is rolled for

The last rule is explicitly to benefit wizards. If you’re a fighter up against a wizard with a staff, you have a choice – you can opt to drop your attack and close range to dispense with subsequent attacks of opportunity from the wizard, but this means that the wizard gets to cast a spell without incurring an attack of opportunity from the fighter; but if you worry about this possibility and choose instead to strike from range, the wizard will get an attack of opportunity. Not particularly threatening, unless the staff has a paralysis effect built in…

Also, this rule is intended to explicitly encourage the use of tumbling and daggers by rangers and thieves, and to make this dexterous style of fighting more interesting. It also means that a thief with a weak weapon can still be dangerous if they have a good tumble skill, since they can close on a fighter with a big weapon and gain attacks of opportunity until the fighter is out of range again. Ultimately they’ll still lose the fight but by pressing the fighter in this way they stay alive longer, enabling another party member to use a wider array of spells and/or missile weapons. You could even allow for the use of feats to extend the sneak attack to this situation, making the in-close thief a really nasty combatant[3].

Also, I would rule that widening the range from a light-weapon fighter involves moving backwards, and can’t be done if there is no backward distance to move. So if fighter engages thief, thief closes in, fighter widens range but backs up to a wall, and then thief closes in again, it’s slice-and-dice time for the fighter[4].

Just as Middenmurk draws on his experience of mediaeval reenactment fighting to construct the initiative rule he proposes, I am drawing here on my experience of knife-fighting and staff martial arts. Once a knife-fighter is inside a longer weapon’s range, the longer weapon becomes a significant hindrance to the user; but closing on a staff with a shorter weapon is all but impossible unless you are very agile.

Attacks of opportunity don’t have to be a significant hindrance to game flow either if, instead of making them an extra roll, you represent them as a bonus on a single combat roll. So everyone declares their actions at the beginning of the round, and anyone who gained an attack of opportunity from someone else gets a +2 on their roll against that person (or grants a +2 on the roll of anyone who is attacking that person). I don’t think this rule is necessary but it can help to reduce the number of rolls in combat, always a good thing. Also, feats can be expended to increase the bonus, which would again benefit thieves and monks.

fn1: you could restrict this to “pole-arms”

fn2: you could extend this to S-sized versus M-sized weapons

fn3: this could be a useful way of making the monk’s unarmed combat nasty

fn4: or, for an unarmed person against this fighter, the unarmed person has grabbed the fighter’s head and is bashing it against the wall