Fighting in Rushing Waters

[MortalPlague]

For next session, I have prepared an encounter that will be fought ankle-deep in torrential water. An earthquake shattered the floor of this room, and it slopes gently towards a gaping chasm. The majestic fountain at one end lost the basin entirely, and its rushing waters form a long, rapid torrent from the north wall to the cliff, thundering over and down into darkness. The battlefield varies in length, from 7 to 10 squares between the north wall and the cliff.

The fight is designed to be a very tough one for my ninth level party. They will be fighting the necromancer ally of a powerful undead knight. The big gimmick to the fight will be the water; this is what I'm thinking:

At the start of each player's turn, they slide two squares towards the cliff. If they begin their turn prone, they slide two additional squares towards the cliff (four total). Any movement made against the current costs two squares per, while any movement with the current may be doubled. A character who moves more than two squares on their turn must succeed on an acrobatics check (DC 20) or fall prone.

This is a balancing act; I want to have some neat terrain rules for the water, but I don't want to cripple the ability of characters to move around. I'm mostly concerned about the 'moving over two squares' bit; is it too harsh? I'd remove it, but I'd like to involve acrobatics in some way. People who train in acrobatics (and thus gain the benefits of 'balance') ought to have an advantage in this sort of terrain.

 

[Jan van Leyden]

What happens to characters going down the cliff? They seem to be out of combat, but how deadly is the drop? If it seems to be very dangerous, staying in safe range seems to be the most important thing for the characters.

For the movement in water I can think of:

- Shift is safe, otherwise Athletics check to remain on feet, or

- All terrain is difficult. After movement make Athletics check to see whether you can act without penalty. Characters who run have to make an Athletics check to remain on their feet.

I think Athletics is better suited that Acrobatics for movement in rushing water, at least if its depth is a bit more than to the ankle.

Do you want to modify forced movement as well? It would be realistic but may be, depending on the enemies, be extremely dangerous.

Another idea would be to make the inclination of the floor not constant but steeper the nearer you get to the cliff. When you fall prone for the first time, it's not a big deal. But the nearer you get to the cliff, the more you - and possibly your allies - have to focus on not being swept away.

 

[FireLance]

The net effect of these rules is that most characters will have to spend a move action every round just to stay in the same place. Even if they give up their standard action to advance against the current, they will have to make a fairly difficult Acrobatics check (especially for untrained, low-Dexterity characters in heavy armor) or fall prone.

If that is not the intended effect of the water, here are a few things you can do to mitigate it:

1. At the start of their turns, the characters only slide 2 squares if the current succeeds on an attack roll: +11 vs. Fortitude defence. Characters trained in Athletics (or Endurance) may use 10 + Athletics (or Endurance) check modifier in place of Fortitude defence.

2. Characters may ignore the penalty for movement against the current if they succeed on a DC 20 Athletics check (this represents fighting against the current while on your feet). Characters may also opt to swim (DC 15 Athletics check, half movement, but no need to make an Acrobatics check to avoid going prone if you move more than 2 squares).

3. Don't double the distance slid for prone characters. They already need to spend a move action to get up.

 

[MortalPlague]

I really want to use Acrobatics over Athletics for two reasons:

1) Athletics gets used for everything. Climbing, jumping, pushing open stuck doors, running somebody down... It's the catch-all physical skill.

2) Acrobatics specifically mentions balance under its benefits.

I might put in an athletics DC, but I'd put it about 5 points higher.


The fall down the cliff itself would not be fatal; though it's a two hundred foot drop, the characters land in water. However, an Aboleth lurks in the water... an 18th level elite monster who would tear anyone apart who landed there. So, yeah, anyone who falls is probably done for. Unless someone is quick enough to lower a long rope...

As for forced movement, I think I'll leave that the same. Too much book-keeping if I change it, and then I'd have to really pay attention to which ones are teleports as opposed to slides, and there are always ambiguous ones...

 

[Mesh Hong]

Its a nice idea for an environmental encounter.

The big questions that need answering are:
1: What advantages (if any) do the enemies have over the PCs in this terrain?
2: If the enemies do not have any advantage in this terrain then why are they fighting here and not withdrawing to a better defencible position?

On to the environment itself.

Just allowing the use of Acrobatics is a little limiting, at the very least I would allow athletics or acrobatics checks.

I would consider making the water difficult terrain, to represent moving carefully being safe, then allow an acrobatics, athletics (or maybe endurance?) for normal movement (on fail they fall prone and slide 2 squares, ending their move action).

I would also consider building in a random or set interval rush of water that either attacked everyones Fortitude defence or called for an athletics/acrobatics/endurance check; on hit or fail the creature is pushed 2 squares (but remains standing). If you did this on a d6 result of 5,6 at the end of every turn it might be quite exciting, and unpredictable.

I would also consider carefully the ramifications of going over the edge, because its going to happen to someone (either a PC or enemy).

aside:
I recently, on the spur of the moment when drawing out a room on the battle map, placed a 10 foot diameter dry well, just to add a little interest. The PCs investigated it and found out it was at least 60 foot deep, then the encounter started and I realised I had placed a serious hazard that could be exploited by my enemies.

Sure enough 3 out of 6 PCs ended up falling down the well which I ruled was 100 foot deep, the first 2 took 65 damage each and the third took 45. Then there was the problem about climbing 100 foot while the rest of the team were fighting a reasonably hard encounter.

No one died and it actually worked out quite nicely, but it is an excellent example of how two concentric circles on a battle map can make a major difference!

 

[Starfox]

If you want to make Acrobatics useful, litter the bottom with stones large enough to protrude out of the water but small enough that you need an Acrobatics check to balance on them.

I second that prone characters should not be pushed more severely; actually I think they should not be pushed at all. Being prone is actually a very good way to fight a stream, and already has its own disadvantages, as mentioned before.

Be prepared for the PCs to shortcut this fight by pushing the opposition off the ledge. If your critters have ANY push powers, be prepared for a few PC deaths. Imagine what pushing someone off the cliff does; even if they make the save to not fall, they are still prone on the edge, where the water in your rules push them over the edge. Very fatal.

 

[Mesh Hong]

Have you considered making this a fight up a cascading waterfall with a number of ledges? That way you get the coolness of the water environment, with multiple much more managable falls. Also the enemies would have a reason to defend the top as it would be a much more tactically sound position.

To me that sounds like a much more interesting fight, one I think I will have to use myself.

 

[Nytmare]

I'd have to throw my hat in with what Mesh is saying.

What I think you are describing is a fight about crossing a conveyor belt, and what I think might be more interesting is a fight about fighting your way back and forth along a conveyor belt.

What I'd go for would be:

• Water is considered rough terrain unless you're moving downstream, INCLUDING moving downstream diagonally
• Athletics (15) to climb the walls or rocks
• Athletics (10) to be able to move upstream as part of your move action
• Acrobatics (10) to move vertically, ignoring rough terrain as part of your move action
• At the start of your turn, if you are not standing near a wall or rock, you get swept downstream orthogonally 1 square
• If you fall prone you get swept downstream orthogonally 1 square
• If you start your turn prone you get swept downstream orthogonally 1 square
• Standing up from prone requires an Athletics (10) check
• +2 bonus to any 'standing from prone' or 'moving upstream' athletics check if you're standing next to rocks or a wall

What these rules are pushing for is to make the characters do a lot of side to side movement across the river to be able to effectively work their way up. I'd be worried that if you have too many penalties associated with trying to move at all in the water, you'll just never see the players getting their feet wet.

Slow characters should find themselves stuck out in the open every once in a while which should force at least one or two of their faster companions to hang back and help them if they get into trouble.

I think that a fight like this will also lead to a bunch of interesting rope tricks. Between tying off safety lines to help people across the river, or to catch people before they get swept off the cliff, to having players tie themselves to each other to stop them from getting carried too far out of a fight.

I'd also probably put in a trip line trap somewhere up top somewhere. Even if it's just a "two guys pull a rope taught, attacking your FORT, and try to knock you off your feet."

 

[MortalPlague]

1: What advantages (if any) do the enemies have over the PCs in this terrain?

The enemies the PCs fight are either skeletons (who I'd rule suffer half the push effect of the river) or flying monsters. The only one who doesn't benefit here is the necromancer herself, and she can teleport back to her rocky perch if she needs to.

I would consider making the water difficult terrain, to represent moving carefully being safe, then allow an acrobatics, athletics (or maybe endurance?) for normal movement (on fail they fall prone and slide 2 squares, ending their move action).

I would also consider building in a random or set interval rush of water that either attacked everyones Fortitude defence or called for an athletics/acrobatics/endurance check; on hit or fail the creature is pushed 2 squares (but remains standing). If you did this on a d6 result of 5,6 at the end of every turn it might be quite exciting, and unpredictable.

That seems like a very good suggestion. I think I'm going to use this.

I would also consider carefully the ramifications of going over the edge, because its going to happen to someone (either a PC or enemy).

How about this: anyone gets a save to avoid going over the edge, letting them fall prone in the square before. If they get pushed further (remember, the river no longer pushes them), they get another save. Failure on the second save has them dangling over the edge, holding on by a hand. Then, they make a DC 15 Endurance or Athletics check each round to hang on. It would require an Athletics check to haul yourself back up, or a friend would have to help you up instead.

I do want the fall to have some lethality about it, but this offers a few chances for the PCs to save each other. I might also reduce the distance the cliff drops so that there's a chance for them to tie ropes together and drop them in time.

What I think you are describing is a fight about crossing a conveyor belt, and what I think might be more interesting is a fight about fighting your way back and forth along a conveyor belt.

What I'd go for would be...

This is a really neat idea. The way my map is setup right now doesn't work well for that, but I might change it up a little bit, narrow the battlefield, and see if I can work in some back and forth play.

 

[Storminator]

If your new river starts carving away the mortar between flagstones, you can easily have some rocks jut out of your river, giving you places where combatants can balance to avoid the push of the river. The water doesn't have to be uniform either - maybe the edges are just difficult terrain (1 square wide) and the center does the pushing.

I would make all the push affects attacks vs Fort and give the river a spot (or maybe a couple spots) in the initiative order. That will make it easier to track when you should apply the push affects. If you use a couple of initiative spots, reduce the amount of push for each attack.

Also consider what happens when PCs start using powers. What if someone puts a Flaming Sphere in the river? Or hits the river with Icy Terrain? Does a Wall spell reroute the river? I don't know what your PCs can do, but be aware they might "attack" the water itself.

PS