Cannons

[Isabella]

Lower quality cannons and cannons produced in lower CL domains would probably have a higher chance of exploding, and an incompetant gunman could lose fingers, even when the cannon fired properly.

Looking at most cannon replicas, I would say they could also be secured by being fastened to an immobile base - it would have to be pretty heavy to counter the recoil.

Just so it's asked and out of the way...

If a darklord fires himself out of a cannon, can he cross the domain border? What happens if he can't?

Horror save for being showered with Darklord parts.
Don't worry, most of them would some back shortly.

[alhoon]

Item: Cannon
Cost: 24000 gp
Damage: 8d6
Critical: x3
Range Increment: 600 ft.
Weight: 7500 lb.
Standard Crew: 6+
Weight of Shot: 42-pounder

Item: Culverin
Cost: 12000 gp
Damage: 6d6
Critical: x3
Range Increment: 450 ft.
Weight: 4700 lb.
Standard Crew: 4
Weight of Shot: 18-pounder

Hmmm. I think the damage proposed is a too low and the range increment too large. As you said cannons should have a range increment of 1500-2000 ft. So I would propose the following changes to your rules:

Cannon:
Damage: 6d6x3
Critical: x2
Range Increment: 350 ft.
Ignores armor and shield bonuses to AC.
The cannon has a maximum range of five range increments, not ten. At the end of the range, the cannonball travels 60' in a straight line before hitting the ground. Anyone in its path takes damage, but each target after the first takes lesser damage by one dice (that is 5d6x3, 4d6x3 etc.) until the cannonball stops.

Culverin:
Damage: 5d6x3
Critical: x2
Range increment: 300 ft.
Ignores armor and shield bonuses to AC.
The culverin has a maximum range of five range increments, not ten. At the end of the range, the cannonball travels 45' in a straight line before hitting the ground. Anyone in its path takes damage, but each target after the first takes lesser damage by one dice (that is 4d6x3, 3d6x3 etc.) until the cannonball stops.

[Rotipher of the FoS]

Considering the weights of the cannons (even a culverin is well over two short tonnes) they most likely need to be pulled by horse, any could only be moved very slowly on the battlefield by hand.

A team of oxen would be more likely. Horses unskittish enough to bring onto a battlefield (all too rare) would be far too valuable to cavalry and messengers for a sensible military force to squander them on haulage.

Just a nitpick, but I've often been miffed that D&D overlooks the central role of oxen in pre-motor transportation. Even the "Arms and Equipment Guide" commits this lapse; you see more examples of triceratops and worgs pulling vehicles, in the game products, than plain ol' oxen! Cattle ain't just for milk and hamburgers, in medieval times, y'know.... :-/

[Brandi]

A team of oxen would be more likely. Horses unskittish enough to bring onto a battlefield (all too rare) would be far too valuable to cavalry and messengers for a sensible military force to squander them on haulage.

I don't know if GURPS High Tech is the best source, though its author had enough of an interest in artillery to satisfy the most dedicated historical grognard... anyway, from his descriptions really heavy guns were generally permanently mounted on fortifications and large guns for siege-breaking were dragged into position on timber sleds (at least pre-1500s). Horses *were* used to pull later cannons, which had improved transport in the form of field carriages, probably because oxen are a LOT slower-- too slow to quickly re-adjust position or possibly even get a piece to the battlefield! Typically, a field-piece had a six-horse team pulling it.