... now with 35% more arrogance!

Monday, March 28, 2011

Catapults and Sieges

Zornhau asked in a comment on my previous catapult post how I would make using catapults as field artillery very difficult. I'm waiting to see what his ideas on this are, though, so I'll make a couple quick notes on other catapult-related things.

One is that some siege weapons (Zornhau mentions a bolt-thrower) are designed to fire directly into and possibly through oncoming enemies. I see these as super-crossbows: use the regular missile rules, but also use the catapult minimum crew rules. Give them an area of effect similar to catapults: 1" wide per die of damage, affecting the target and potentially those behind the target, up to 1" per die of damage. They do not have a minimum range, the way other catapults do, but they also have penalties for indirect fire, the way archers do.

The other bit I wanted to mention was how to use catapults in an actual siege, destroying castle walls. I haven't worked out hard rules for this, but I think, rather than assigning structural hit points, it would be simpler to use the standard 2 or less Change Situation roll to see if a wall or structure is damaged by catapult fire; just roll the damage dice and treat both results as a situation roll. Thicker walls or harder substances increase the difficulty, choice of ammunition can decrease it (barrels of flaming oil would be extra effective against an oaken gate, for example.) Success means a section of wall 1" wide per die of damage is destroyed.


  1. This book might be illuminating...


  2. ballistae firing incendiaries I could get behind. I generally make mangonels and trebuchets too inaccurate/unpredictable to be used effectively against walls - they're mostly used for lobbing dead donkeys to spread diseases. Sapping's the way to go in my campaign.

  3. Depends on how much reality you want. Modern tests on trebuchets show them to be very accurate indeed. The Romans used torsion catapults to take down walls.

  4. ha! I get schooled for using out of date sources - thank you.
    I always thought the big problem with trebuchets was not knowing ahead of time how far the projectile would go. Maybe that's more of a problem with a wobbly, non-streamlined projectile like a dead horse. Maybe it's just that it took a few tries for that farmer in England to tune up his machine? anyway, good to know.

  5. Assuming you have a consistent sling release mechanism, then the weight of the missile is negligable compared to that of the counter balance, so the missile normally leaves the sling at the same velocity, regardless of weight and always hits round about the same spot.

    There was a documentary years back where they built a trebuchet in Scotland and knocked down a specially constructed replica wall. IIRC they took a couple of tries to to get on target, much like WWII era artillery.

    I doubt the farmer in England had a very good machine...