View Full Version : DF-style lava floodgate: What would it take?

2009-07-31, 04:29 PM
Is there some way this could work without enchanting the floodgate with total fire immunity? Exposure to lava deals 2d6 damage, and immersion is 20d6 per round. I wasn't sure how much damage lava against a wall would do.

Adamantine has hardness 20, but the lava if it's immersion damage does an average of 70 damage. And an adamantine floodgate would be like 5 million gp. +5 enhancement (10 hardness) and 10 fire resistance would be 43,000 gp...

Though then there's also Fire Warding, which absorbs 50 points, but that's a +6 epic enhancement.

2009-07-31, 04:56 PM
...are you that crazy guy who was trying to build a 3.5 Campaign based on Boatmurdered?

2009-07-31, 05:14 PM
I would rule that a wall is not immersed until it is surrounded on all four sides, so adamantine would do.

2009-07-31, 05:15 PM
If it only has lava on one side it's not submerged. At most you should do 10d6 damage for being half submerged.

I'd probably just do the 2d6 instead.

2009-07-31, 07:06 PM
Alright, thanks. And no, I'm not, though I have had thoughts of simulating Dwarf Fortress with D&D. Also, I discovered that using regular steel and enchanting it with +5 is a loooot easier...jesus, a floodgate made entirely of adamantium would cost like 5 million gp. Although, I suppose there could just be an adamantine sheet over a regular floodgate...

2009-07-31, 07:18 PM
Well, you are talking homebrew here. No need to go with something strictly by-the-books. Just make a material that's resistant/immune to lava damage.fire damage. Some kind of high-melting temperature rock or something.

2009-07-31, 07:24 PM
What is the cost for an at-will item of "Cone of Cold"? As a GM I would let that enchantment be built into the enchantments on the doors and counter the heat damage on a die for die basis, but that might have to be carefully controlled (manually?) to keep a solid plug of rock from forming in the lava, such that it would not flow when the gates were opened.

My professional opinion as a degreed (but not practicing) mechanical engineer is that if there is only lava on one side, then they are only taking 10d6 damage per round. You need to make sure the doors open UPWARDS, or they will melt the first time you open the gates unless they fit to the sides of the channel close enough to avoid letting any lava worth mentioning seep around behind them.

2009-07-31, 07:27 PM
Oh boo. I found that guy an another forum once. The campaign sounded hilarious, but he stopped posting.

2009-07-31, 07:44 PM
Energy Attacks
Acid and sonic attacks deal damage to most objects just as they do to creatures; roll damage and apply it normally after a successful hit. Electricity and fire attacks deal half damage to most objects; divide the damage dealt by 2 before applying the hardness. Cold attacks deal one-quarter damage to most objects; divide the damage dealt by 4 before applying the hardness.

Your looking at between 1d6 and 10d6 a damage per round, based on interpretation.
If 1d6, Stone blocks it completely.
If 10d6, Thats 35/2 = 17.5 on average, with 60/2 = 30 at maximum. Adamantine Would, on average, negate it.

So Take 5 inches of Adamantine, for 200 HP and 20 hardness.
You need to exceed 40 damage on 10d6 to damage it. According to SmallRoller (Nice program when your lazy), you roll above 40 on 10d6 less then 0.01% of the time. So, I'm assuming (Since I'm lazy) 0.004%.
A day has 14,400 rounds, which means 14,400 rolls. 14,400*0.004 = 57.6 rolls beat it in a day. It takes between 1 and 10 damage on each of these rolls. So at worse, it'd burst in a day.

You can get around this problem by: Strengthening the metal (Off the top of my Head, Artificer infusions can do this), or by making it stupidly thick and just keep reinforcing it.

Edit: Program was being stupid, It's actually 11.60% to get 42 or higher on 10d6 (1670.4 Rolls a day gets past hardness). If you make its hardness +5, it becomes 0.07% to get 52 or higher on 10d6. (100.8 a day)

2009-07-31, 07:46 PM
Or just enchanting the metal. Automatically stops the 1-10 damage (http://www.d20srd.org/srd/magicItems/magicArmor.htm#fireResistance).

2009-07-31, 07:51 PM
Or just enchanting the metal. Automatically stops the 1-10 damage (http://www.d20srd.org/srd/magicItems/magicArmor.htm#fireResistance).

Or that, yes.

2009-07-31, 07:59 PM
I would guess it deals contact damage as opposed to full immersion damage, which, following the rules stated by gralamin, negates all the damage that would have been dealt.

I would assume that because a volcano's cauldron doesn't just cave in the moment it starts existing and it is fairly non-magical stone there.

2009-07-31, 08:24 PM
Well, adamantine is 5 times as expensive as mithral, which is 500 gp per round. I suppose it could just be a steel floodgate, and give it a +5 enhancement and fire resistance. That would be 43,000 gp plus the price of the floodgate, and would negate it permanently. I would think this floodgate would be at least a ton, which would be 5 million gp. (Plus, you probably can't even get that much adamantium and making the floodgate would be agonizing without high level magic. (So on top of that you've got spellcaster fees)

2009-07-31, 10:11 PM
Or you could have a wall of force that is illusioned to look like whatever you want.