Underwater Combat is Hard!

Here's a comic to illustrate the point. I'm coming from a Pathfinder perspective, but fighting under water seems to be complicated across systems. My question is this:

Have any of you guys used underwater combat rules to good effect? Did you release the kraken? Hold an underwater intrigue in the court of the Marlin King? Mistake a dragon turtle for a tropical hideaway? How do you turn these fiddly rules into a memorable encounter?

I've posted about these a few times, and most of my "memorable" encounters were only memorable in terms of what a pain they were.

Questions that always come up:

1) Can a person with Freedom of Movement actually swim, or are they relegated to walking?
2) Why is it easier to swing a Spiked Chain or Ranseur, or even a Morning Star, than a longsword? (First three are Piercing and do normal damage, last is Slashing and does half.)
3) Successful Swim check means 1/4 movement, which is a pain for creatures with 30 feet. How do you handle that?

In your cartoon example, "Mr Stabby" would work just fine as a stabbing (i.e. Piercing) weapon. It's Mr. Slice and Dice that presents a problem.

Our solution to the combat situation was to change the rules slightly. It's "Thrusting" weapons that do full damage, a category based on how they're used rather than the type of damage they do. You can bludgeon someone with the end of a staff, when you jab with it, and that makes it a thrusting weapon. Similarly a Longsword can be used as a Thrusting weapon.

The caveat was, if it's not normally used as a Thrusting weapon, the character only gets half of their Strength bonus to damage.

The combat ritual should be:

1) Make a Swim check, to see if you can move or use Dex to defense this round.
2) Make Con checks, as needed, if the PC is holding their breath.
3) Make Attacks and or Moves as desired. Note that movement is 1/4 for a single move. For a 30 foot base move creature, that's one square one round and two the next. (PITA!)
4) Make Concentration checks for any spells being cast. (Note that none are needed if the caster can breath under water.) (Secondary note: First spell cast better be one to let caster breath under water.)

Also be aware that there are no 5 foot step maneuvers under water, unless the character has a swim speed or Freedom of Movement.

Role Playing scenes in an underwater setting aren't that different from RP anywhere else, so meeting with the Marlin King isn't any different from meeting with the owner of the Oakland A's.

Over all though, the best approach I've found to underwater adventuring is to ignore the fact that the party is under water, until and unless combat comes up. The fact that it takes them four times longer to cover a distance just means that more time elapses between events. Since we only really deal with the events, who cares? So long as they have a way to breath, let the game play out.

I like Alluria Publishing Cerulean Seas campaign, though it's a setting, the main book is filled with interesting rules for undersea environments like water pressure levels, buoyancy, light zones, as well as classes, races, monsters, feats, spells, magic items, etc. However, yeah, 3D combat is a pain. I've seen people use poker chips of different color (say each blue chip equals 5' height, while red chip equals 20 feet or negatives) and you place the chips under your figurine to determine different levels of depth in water - not everyone is on the same "plane". Also Cerulean Seas has a tactic using javelins with gas filled bladders attached that you let go beneath your intended target for a unique underwater combat tactic. They have other books on areas like the abyssal (sea bottom environs), etc. Worth checking out, I think.

gamerprinter said:

I like Alluria Publishing Cerulean Seas campaign, though it's a setting, the main book is filled with interesting rules for undersea environments like water pressure levels, buoyancy, light zones, as well as classes, races, monsters, feats, spells, magic items, etc. However, yeah, 3D combat is a pain. I've seen people use poker chips of different color (say each blue chip equals 5' height, while red chip equals 20 feet or negatives) and you place the chips under your figurine to determine different levels of depth in water - not everyone is on the same "plane". Also Cerulean Seas has a tactic using javelins with gas filled bladders attached that you let go beneath your intended target for a unique underwater combat tactic. They have other books on areas like the abyssal (sea bottom environs), etc. Worth checking out, I think.

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I agree with this, after reading through Cerulean Seas it really does a good job of covering all the necessary physics in a way that is neither needlessly complicated nor overly gamey.

But I generally agree that 3D combat is difficult, but that's a human brain thing, we're not good at thinking in 3D.

From my own experiments I have always tried to keep things simple, since outside of the campaign that is 100% underwater, people's play in watery environments is going to be limited to perhaps a few sessions tops, or only small portions of a session. I tend to keep the rules very simple:
If you have no swim speed, you make a swim check and move half speed.
If you are carrying more than half your light load you sink (-5ft/round).
If your are not trained in underwater combat you have penalties to your attacks.

That keeps the game moving smoothly without everyone having to come up with complex adjustments to tactics and gear every time they hit water combat.

For more in-depth (buh-dum tish!) underwater adventures I defer to Cerulean Seas and others who've done it better.