The Physics and Limitations of Water Walk

[KanedaX321]

This is one of those "The Rules Aren't Anywhere" kind of questions, but I'm at least hoping for an opinion...

In their next encounter, my group will be hijacking a galleon from a dock. The plan so far, unbeknownst to them, is to give them (and me) a little experience with aquatic combat by stocking the water around the boat with some sahuagin minions.

However, before setting off, the wizard in my group picked up a Water Walk ritual from a local seller. My assumption is that he'll cast the ritual on the party and they'll walk across the harbor rather than do a land or swimming approach.

So does anyone have any thoughts about how to merge aquatic and ground combat? I assume the sahuagin would have to surface to attack the walkers, and the walkers would have to submerge to attack the underwater sahuagin. I'm picturing something along the lines of a sandworm-type combat, only the PCs can go under the sand to attack the worms.

Also, if, for some reason, the sahuagin try to drag the PCs under, any ideas about 1) if that's something that could even happen (Water Walk treats the water as solid ground, or 2) what kind of saves the PCs would have to roll to stay above water. Strength? Will to keep the ritual active?

Again, this is all theoretical, I'm just making sure I can cover my bases if things start to get weird.

 

[Zaphling]

as i can see it, 3D combat still applies to this. Walkers can still attack creatures who are adjacent to them, even if the enemy is below them. and those underwater can still attack surfacers, as long theyr adjacent.

Creatures who wants to drag a PC underwater must still follow the rules for grabbing and dragging (although I dont remember the dragging rule).

 

[Rechan]

Here's how I'd do it. You could Either:

1) The simple approach: All characters on the surface have a -4 to attack enemies submerged. PCs underwater attacking underwater opponents have a -2 to attacks (I believe this is how aquatic combat works anyways for anyone who doesn't have the Aquatic keyword)

OR

2) The more finicky approach: Ranged weapons can fire from surface down into the water as far as their close range distance. Magical attacks (That aren't fire) have their range halved - bursts/blasts lose 1 square. Melee from the surface doesn't work unless the character has a spear (so characters would have to submerge as you prefer in order to engage).

However if it was me as a DM, I'd treat the surface of the water as a sort of flat plane that PCs call fall through. Meaning that if a PC is knocked prone, they go into the water. And for them to go from in the water to standing on it, they need to spend a standard action to "stand up" (like they were climbing onto a platform from inside water).

 

[KanedaX321]

2) The more finicky approach: Ranged weapons can fire from surface down into the water as far as their close range distance. Magical attacks (That aren't fire) have their range halved - bursts/blasts lose 1 square. Melee from the surface doesn't work unless the character has a spear (so characters would have to submerge as you prefer in order to engage).

However if it was me as a DM, I'd treat the surface of the water as a sort of flat plane that PCs call fall through. Meaning that if a PC is knocked prone, they go into the water. And for them to go from in the water to standing on it, they need to spend a standard action to "stand up" (like they were climbing onto a platform from inside water).

I'm liking this idea, especially the prone aspect. It's Water WALK, after all, so it would assume that if you fall you fall in.

I might have to write up a whole personal rulebook about this upcoming encounter, just in case. I'm thinking about concealment: Underwater creatures have -2 concealment against surface, and vice versa, especially at night or in certain weather (Might add some rain to mix things up a bit). Sahuagin that attack and don't make a move or shift action back underwater will be considered "on the surface" and can be attacked with regular melee. Etc. Etc. Etc.

Man, there's a lot to think about... thanks you guys!

 

[Rune]

Keep in mind, also, that, depending on the condition of the water, it might block line of sight, as well.

 

[Rechan]

Keep in mind, also, that, depending on the condition of the water, it might block line of sight, as well.

Concealment or blocking line of site is a good point, but it depends on the water.

Compare the sea outside of the Carribean and the sea outside of Seattle or London. One is so clear you can see the bottom, the other is so murky. Also waves would be a problem (and I wonder how waves would interact with Water Walk? Become difficult terrain?)

And once you start killing Sahuagin, their blood is going to murky up the water in the space they take up. Any monster in a space UNDER a dead sahuagin would have decent concealment.

 

[KanedaX321]

Concealment or blocking line of site is a good point, but it depends on the water.

Compare the sea outside of the Carribean and the sea outside of Seattle or London. One is so clear you can see the bottom, the other is so murky. Also waves would be a problem (and I wonder how waves would interact with Water Walk? Become difficult terrain?)

And once you start killing Sahuagin, their blood is going to murky up the water in the space they take up. Any monster in a space UNDER a dead sahuagin would have decent concealment.

The PHB lists choppy water as difficult terrain. The dock itself is on Turnabout Island in the Eberron system in the winter: Not quite Arctic, but pretty dang close. It's not going to be sky blue waters.

Blood in the water... it's disgusting, it's one other thing to think about, but damn if it's not a great idea. Differentiating between attack types, of course: Hitting someone with a melee or ranged weapon attack, or something physical, would cause it, but hitting them with a psychic blast or some kind of elemental attack wouldn't since charring a corpse with lightning or poison wouldn't cause bleeding.

If a body remains, it could be just one more vantage point obstacle. Then on the corpse's next turn, it could expand into a burst 1 of partial concealment as it bleeds into the water. Corpse's next turn that burst will disappate, but the body itself remain there until the end of the encounter. Or it will move one square towards the shore every turn thereafter as the waves or tide pull it in.

 

[Rechan]

Well you don't want to get too complicated with your rules. Otherwise it's going to cause some confusion and slow down the session certainly. Especially if the PCs are just fighting sahuagin minions. Although a monster that can grab (then drag someone under water) might be cool.

 

[Ryujin]

For simplicity's sake, I think that I would just treat the water as solid ground, where the Water Walkers are concerned. If they don't want to be submerged, then they aren't, as per the ritual's description. In its most simple form it's just like fighting small aerial opponents.

So the question then becomes how do you get them to want to be submerged? The sahuagin use longspears, for reach? Crossbows as spear guns? Magic?

 

[(Psi)SeveredHead]

It's not in the MM, alas, but sahuagin do occasionally use poisoned crossbows in lore (I'd make a special artillery with poisoned crossbow as an encounter/recharge attack if I were to use this type of sahuagin). Also, spiked nets.

And in the MM1, of course, the priestess has the ability to blast enemies at very long range while underwater, in addition to locking them in place with her recharge ability.

IMO, unless a PC is aquatic, they may suffer a concealment penalty to attack anything underwater, due to the "bending of the light" effect, whereas the sahuagin wouldn't suffer this, being used to this kind of combat (I wouldn't allow Stealth in this occasion, even though it would be within the rules). If the water is murky, upgrade to total concealment, giving more opportunities for stealth.

I don't know if the PCs would want to go underwater. I don't know if Water Walk keeps their gear dry, they probably don't all have Athletics, you haven't mentioned if they have the Water Breathing ritual, and the sahuagin have greater swim speeds and +2 to hit anything underwater. However, using Water Walking sounds cool here; I'd expect the sahuagin to be "out of position" for this kind of attack, having taken good tactical positions for ship-based combat instead.

I don't believe there's anything in the rules against hurling fire magic from above water to detonate below water.