This question becomes very important to clerics (or any class unable to use spears/polearms) who want to use a melee weapon to attack from the second rank.
The actual historical English quarterstaff almost certainly should have as much reach as a spear, due to its great length. Quarterstaff combatants often make thrustring strokes that greatly exceed the range of a sword. However, many implementations of D&D (including ACKS) allow it to be used 1-handed, making me visualize it as intending to represent a smaller Gandalf-esque walking staff -- more like an oversized club.
The only relevant rule I could find in ACKS is the one on sundering weapons, which classifies staves as being vulnerable to breakage like spears. That seems to suggest that a longer staff is intended. Is there a more explicit listing somewhere?
Can a quarterstaff poke something the same as a spear? Absolutely. Will a poke from a quarterstaff have the same effect as a poke from a spear? probably not. Hence I would say a quarterstaff does not reasonably have reach, not because it can't hit from that range, but because it couldn't damage from that range.
Can a quarterstaff poke something the same as a spear? Absolutely. Will a poke from a quarterstaff have the same effect as a poke from a spear? probably not. Hence I would say a quarterstaff does not reasonably have reach, not because it can't hit from that range, but because it couldn't damage from that range.
[/quote]
And yet, that's manifestly how staffs were used. Not simply bonking people on the head, but with what we could call "spear-thrusts" (plus some dynamic sweeps as well). If you must, maybe reduce it back to a d4 damage when used two-handed but with reach, though a two-handed spear is already d8, so I'm not sure I would.
My understanding of staff fighting (which is admittedly limited) is that while thrusts were absolutely a part of it, a staff isn’t held the same way a spear is when thrusting. A spear is thrust with one hand (allowing a grip anywhere along the haft, depending on distance to target), while a staff is thrust with one hand on the base and one hand between 1/4 and 1/2 way up the staff.
The grip difference makes a big difference in effective reach, even though the motion of the weapon is the same, and is the big reason why I would say that they do not have reach.
If you must, maybe reduce it back to a d4 damage when used two-handed but with reach, though a two-handed spear is already d8, so I'm not sure I would.
[/quote]
That was what made sense to me, too. When I watch video of staff duels, it seems like there are strong short strikes that use both hands to provide more leverage (the 1d6 damage mode), and weaker thrusts that have full reach but are really more like one-handed strikes in terms of their force (the 1d4 mode). It's encouraging to see someone else come up independently with the same idea.