Combat (and other activity) Underwater

[Erik_Nielsen]

Phil Masters remarked in a recent thread that rather than putting out a new version of Atlantis for 4e, "you can mix stuff from the 3e Atlantis with the rules for pressure and drowning and such from the 4e Basic set."

Rolling with that idea, I'd like to get the HiveMind's take on bringing certain concepts from 3e Basic and 3e Atlantis into 4e. I'd also like to take this opportunity to suggest that an Atlantean (or Waterworld or Blue Planet or, well, anything Aquatic) theme would make for an excellent issue of Pyramid; here's a handy collection of water-based GURPS for your research convenience.

Combining 3e's rules for Combat in and under the water with the rules for combat in 3e Atlantis (and adjusting so as to not contradict anything in 4e Basic):

Combat in General

Fighting in and under water is tiring! Make a Swimming roll every 5 or 2 seconds in Combat in or under water, respectively, or lose 1 FP. Presumably, this could be modified for 4e such that seconds spent Doing Nothing don't count against those 5 or 2 seconds. Amphibious and Aquatic creatures are not subject to this.

Melee Combat

Skill penalties for Melee combat underwater: -2 for Reach C weapons (including hands and feet), -4 for Reach 1, -8 for Reach 2, and a further -4 per additional yard of Reach; Amphibious or Aquatic creatures have no penalty for Reach C, -1 for Reach 1, and an additional -2 per yard of Reach after that. Also, -1 skill penalty for each level of Encumbrance (i.e., -1 for Light, -2 for Medium, etc.). Skill penalties are halved if you're _in_, not under, the water.

Melee damage is halved underwater, but only reduced by 1/3 if you're fighting _in_ water, not under it. 3e Atlantis suggests breaking this down further: underwater, thrusting impaling damage would only be reduced by 1/3, while damage from large-surface weapons that require a roundhouse swing (like a two-handed axe) would be reduced by 2/3.

Ranged attacks:

Thrown Weapons have 1/2 and Max ranges divided by 10 and have their damage reduced by a further 1/2 just for being underwater. If this reduces max range to 1 or less, they can't be thrown effectively.

Bows and Crossbows either don't work, or, if they're specially crafted to work underwater, use the same rules as for Thrown Weapons.

Black Powder Weapons don't work unless magically or alchemically built to do so; if so, treat as other guns.

For Guns and Missiles, see High Tech [HT85]. For Lasers and Beam weapons, see their respective entries in Ultra Tech.

For Explosives and Explosions, see Explosions in Other Environments [B415].

Vision and Visibility

Note that underwater vision without mitigators like goggles or Nictating Membrane results in a condition very similar to Hyperopia, AKA Bad Sight: Farsighted [B123]; contrarily, individuals with extreme Myopia, AKA Bad Sight: Nearsighted, may be able to "see underwater with the naked eye." I suggest that we treat normal vision underwater as the same as Bad Sight: Farsighted (and treat it as a mitigator to Bad Sight: Nearsightedness), subject to mitigation by goggles or Nictating Membrane.

Other Skills (a suggestion):

The description for Amphibious [B40] says, "You do not suffer skill penalties for working underwater." This implies that non-Amphibious (or Aquatic) individuals should suffer some sort of penalty to skill just for working in water. Perhaps this implies a sort of Technique, like:

Working Underwater (Hard)
Defaults: Prerequisite skill-4
Prerequisites: Any DX-based skill normally not performed underwater

This technique allows you to buy off the basic penalty for non-Amphibious and non-Aquatic creatures to perform normally non-aquatic DX-based skills (e.g., Typing, Traps, Symbol Drawing, Pickpocket, etc.) underwater.

Or, in light of Perks like Armorer's Gift [HT249], perhaps this is a Perk for one specific circumstance, such as:

Perk: Trained Underwater [1]

You've undergone special training to mitigate all penalties to perform one specific task underwater. You must specialize by skill.

Rules and Pages

Finally, a Rules Dump. Rather than reprinting information from 4e books, here are the page numbers:

Advantages/Disadvantages:
Amphibious [B40]
Doesn't Breathe [B49]
Nictating Membrane [B71]
Pressure Support [B77]
No Legs (Aquatic) [B145]

Skills:
Aquabatics [B174]
Environment Suit/TL (Diving Suit) [B192]
Scuba/TL [B219]
Swimming [B224]

Rules:
Move in Other Environments [B18]
Holding Your Breath [B351]
Swimming [B353]
Dodge and Drop while Swimming [B377]
Aerial Attack and Defense (a good basis for multi-level combat) [B398]
Explosions in Other Environments [B415]
Pressure (as a Hazard) [B435]

[Crakkerjakk]

I'd also give a MASSIVE penalty for at least dodge if completely underwater. Moving is slow and it's a lot harder to do anything except rotate around your center of gravity.

I'd expand the "not taking FP loss" clause from Do Nothing to a pretty much any action that isn't a move, attack, or active defense.

I was a life guard and qualified at the highest level of swimming competence in the Marines before they start sending you to schools to train you. One thing I would make sure you represented is the FP loss for exertion and being able to hold your breath. A lot of drowning victims will try to climb on top of you to get to air in their panic. For the most part if you keep your cool and get a breath before you go under, the wisest course of action is to let them push you down without resisting, and then swim back to the surface at an angle so you're out of their reach when you surface and try again.

In the Corps I used the same procedure to get through my swim qual. You're required to "save" the swim instructors, and if they pull you under while doing so, you're supposed to use these pressure points to get them to let go. The instructor I was supposed to be saving (a big burly guy who probably outweighed me by ~50 lbs) wasn't letting go. So I just went limp. It took more oxygen for him to keep me grappled and underwater than it did for me to just float there, so he had to surface before I started freaking out from oxygen deprivation. I surfaced after he let me go and dragged him the rest of the way to the pool wall.

Anyway, these are basically the Holding Your Breath rules, but I think they're really important (and probably overlooked) in underwater combat. I think the example also shows that the rules for lifesaving from the Swimming chapter are a bit too strict. According to that, you have to wait a minute after a failed attempt to save someone from drowning. It's probably only more like 10 seconds even if they freak out and push you under.

[davidtmoore]

This is awesome, as I just now logged on to the forum to see if anyone had anything to say about underwater combat!

Combining 3e's rules for Combat in and under the water with the rules for combat in 3e Atlantis (and adjusting so as to not contradict anything in 4e Basic):

Combat in General

Fighting in and under water is tiring! Make a Swimming roll every 5 or 2 seconds in Combat in or under water, respectively, or lose 1 FP. Presumably, this could be modified for 4e such that seconds spent Doing Nothing don't count against those 5 or 2 seconds. Amphibious and Aquatic creatures are not subject to this.

Yep, awesome.

Melee Combat

Skill penalties for Melee combat underwater: -2 for Reach C weapons (including hands and feet), -4 for Reach 1, -8 for Reach 2, and a further -4 per additional yard of Reach; Amphibious or Aquatic creatures have no penalty for Reach C, -1 for Reach 1, and an additional -2 per yard of Reach after that. Also, -1 skill penalty for each level of Encumbrance (i.e., -1 for Light, -2 for Medium, etc.). Skill penalties are halved if you're _in_, not under, the water.

Melee damage is halved underwater, but only reduced by 1/3 if you're fighting _in_ water, not under it. 3e Atlantis suggests breaking this down further: underwater, thrusting impaling damage would only be reduced by 1/3, while damage from large-surface weapons that require a roundhouse swing (like a two-handed axe) would be reduced by 2/3.

Hmm... I don't think you become much less accurate when trying to fight underwater, just slower. I appreciate that in combat, slower means less effective, but I'd want to assess this as a bonus to target's dodge rather than a penalty to my skill. Also, I dislike the skill-penalty by weapon reach; it shouldn't really affect thrusting weapons, and swung weapons are basically useless underwater anyway. Finally, damage penalties in 4e are usually assessed as damage-per die rather than multipliers (other than the armor/damage type divisors).

I'm inclined to suggest the following:

Melee Attacks

All Maneuvers and Techniques are available, as long as they make sense in the environment (GM's option).

-1 to skill (can be bought off with a perk, "Aquatic Combat", specialised in the skill) and skill cannot exceed Swimming skill; Aquatic and Amphibious characters disregard both penalty and limitation. Dodge and damage affected as follows:

Unarmed attacks, Close Combat weapons and all thrusting weapons:
+2 to target's dodge (can be reduced with Deceptive Attack)
-2 to damage, or -1 damage per die, whichever is worse.

Swinging weapons with a reach up to attacker's SM+1
+4 to target's dodge (can be reduced with Deceptive Attack)
-3 to damage, or -2 damage per die, whichever is worse.

Swinging weapons with a reach of attacker's SM+2 or higher cannot be effectively used underwater.

Note that Slams do not suffer the above damage limitation, as the character's reduced Move directly affects the damage done anyway.

Defenses

Parries and Blocks are at -1 to effective skill (can be negated with the relevant Aquatic Combat perk) and cannot exceed (Swimming/2)+3, not including Combat Reflexes. Aquatic and Amphibious characters ignore both the penalty and the limitation.

Dodge is based on the lower of your swimming speed and Basic Speed, before adding the +3 or factoring Combat Reflexes; this gives Aquatic and Amphibious characters an inbuilt Dodge advantage.

Ranged attacks:

Thrown Weapons have 1/2 and Max ranges divided by 10 and have their damage reduced by a further 1/2 just for being underwater. If this reduces max range to 1 or less, they can't be thrown effectively.

Bows and Crossbows either don't work, or, if they're specially crafted to work underwater, use the same rules as for Thrown Weapons.

Black Powder Weapons don't work unless magically or alchemically built to do so; if so, treat as other guns.

For Guns and Missiles, see High Tech [HT85]. For Lasers and Beam weapons, see their respective entries in Ultra Tech.

For Explosives and Explosions, see Explosions in Other Environments [B415].

I kind of just want to say you can't throw underwater either? But yes, otherwise. I'd suggest the damage modifier for thrown weapons be -3 or -2 per dice, whichever is worse.

Vision and Visibility

Note that underwater vision without mitigators like goggles or Nictating Membrane results in a condition very similar to Hyperopia, AKA Bad Sight: Farsighted [B123]; contrarily, individuals with extreme Myopia, AKA Bad Sight: Nearsighted, may be able to "see underwater with the naked eye." I suggest that we treat normal vision underwater as the same as Bad Sight: Farsighted (and treat it as a mitigator to Bad Sight: Nearsightedness), subject to mitigation by goggles or Nictating Membrane.

Okay, although I would tend away from automatically making being underwater a mitigator for near-sightedness. I might suggest that a player who wants his character to be able to see clearly underwater take Nearsightedness with a mitigator: Except underwater, and Nictating Membrane.

Other Skills (a suggestion):

The description for Amphibious [B40] says, "You do not suffer skill penalties for working underwater." This implies that non-Amphibious (or Aquatic) individuals should suffer some sort of penalty to skill just for working in water. Perhaps this implies a sort of Technique, like:

Working Underwater (Hard)
Defaults: Prerequisite skill-4
Prerequisites: Any DX-based skill normally not performed underwater

This technique allows you to buy off the basic penalty for non-Amphibious and non-Aquatic creatures to perform normally non-aquatic DX-based skills (e.g., Typing, Traps, Symbol Drawing, Pickpocket, etc.) underwater.

Or, in light of Perks like Armorer's Gift [HT249], perhaps this is a Perk for one specific circumstance, such as:

Perk: Trained Underwater [1]

You've undergone special training to mitigate all penalties to perform one specific task underwater. You must specialize by skill.

More inclined to Perk that Technique, as being able to work underwater is a pretty rare circumstance for most campaigns. Also I note that Explosives: Demolition and Explosives: Underwater Demolition default to each other at -2, so I would regard this as a pretty minor penalty most of the time.

Rules and Pages

Finally, a Rules Dump. Rather than reprinting information from 4e books, here are the page numbers:

Advantages/Disadvantages:
Amphibious [B40]
Doesn't Breathe [B49]
Nictating Membrane [B71]
Pressure Support [B77]
No Legs (Aquatic) [B145]

Skills:
Aquabatics [B174]
Environment Suit/TL (Diving Suit) [B192]
Scuba/TL [B219]
Swimming [B224]

Rules:
Move in Other Environments [B18]
Holding Your Breath [B351]
Swimming [B353]
Explosions in Other Environments [B415]
Pressure (as a Hazard) [B435]

Much appreciated!

Hope my contributions are useful. You've certainly helped me formulate my own ideas.

[Ragitsu]

You sir, rock. This will be handy if I ever run underwater combat.

[davidtmoore]

Why thank you.

I just thought of another one that bears mentioning:

Knockback is always halved underwater.

[davidtmoore]

Scratch that; call it 1/5, like Swimming speed.

[Anthony]

Originally Posted by davidtmoore

Okay, although I would tend away from automatically making being underwater a mitigator for near-sightedness.

Yes, while it may possible for water to randomly give the exact correction needed for good vision, it's very unlikely. Also, my personal experience is that underwater vision (without goggles) is blurry at all ranges, not either near or far sighted.

[davidtmoore]

Sincerely sorry about rapid-fire posting, but I keep turning over new ideas. This is my last.

Nets (Skill: p.B211, Stats: p.B276) have a Max of (ST/2)+(Skill/5), which is unlikely to exceed 20 (ie. 2 after applying the range divisor above), and so would normally not be allowed as throwing weapons according to the rules above. As they function by entangling, however, a Net with an effective range of at least 1 can be thrown underwater to intercept a moving opponent.

If the target has moved at least two yards in its previous turn and the attacker is adjacent to it, or can reach it with a step or Move and Attack, then he is a legitimate target. Roll at -1 to skill (can be negated with the relevant Aquatic Combat perk) and resolve per the Net rules; the target is at +2 to dodge or parry.

There you go. Add that to Spear and you have the net-and-trident-wielding mermen all over you.

[Erik_Nielsen]

See now, this is serendipity: I was just lamenting to Phil Masters that this thread had pretty much sunk like a stone (pardon the pun), when you fine fellows picked up the banner. Awesome!

Originally Posted by Crakkerjakk

I'd also give a MASSIVE penalty for at least dodge if completely underwater. Moving is slow and it's a lot harder to do anything except rotate around your center of gravity.

Originally Posted by davidtmoore

Dodge is based on the lower of your swimming speed and Basic Speed, before adding the +3 or factoring Combat Reflexes; this gives Aquatic and Amphibious characters an inbuilt Dodge advantage.

These are both very interesting ideas. The feeling I get for Dodge from the Forums is that it includes any kind of twisting, turning, ducking, or weaving to get out of the way of something about to hit you. While I agree that there ought to be a penalty, reducing Dodge to Swimming Move + 3 would be murder on any normal human (since, after all, the most Swimming Move JQMortal is likely to have is 3 [ (Basic Move / 5) + 2 max], so we're talking a maximum Dodge of 6 for any humans in the water).

I propose, instead, a penalty of -3 (not as severe as, say, being Stunned, but still pretty penalizing). That way, your Ninja, with her usual 15- Dodge, can twist out of the way of Bondo-san's spear gun on a 12-, whereas Warez Wally, Bondo-san's bumbling sidekick, is still stuck with a 5-.

Thoughts on a happy medium?

Originally Posted by Crakkerjakk

I'd expand the "not taking FP loss" clause from Do Nothing to a pretty much any action that isn't a move, attack, or active defense.

This is reasonable to me. Perhaps we could expand it to include Evaluate, Aim, and Concentrate, since these are non-active maneuvers. I don't recommend including Ready, since it already implies some kind of movement.

Originally Posted by davidtmoore

Hmm... I don't think you become much less accurate when trying to fight underwater, just slower. I appreciate that in combat, slower means less effective, but I'd want to assess this as a bonus to target's dodge rather than a penalty to my skill. Also, I dislike the skill-penalty by weapon reach; it shouldn't really affect thrusting weapons, and swung weapons are basically useless underwater anyway. Finally, damage penalties in 4e are usually assessed as damage-per die rather than multipliers (other than the armor/damage type divisors).

By "bonus to target's dodge," do you mean like the +2 to defenses for Telegraphic Attack [MA113]? That's an interesting way to get around the drag effect on swung weapons. That said, drag is a serious factor both on damage and accuracy; I do not feel comfortable simply doing away with to-hit penalties, although I could be talked into reducing them, especially with the dodge bonuses. Perhaps a -2 for swinging weapons?

For thrusting weapons, I've seen a significant bend when attempting to use a spear under water. Water resists significantly; you may think you're thrusting true, but there's a definite bias to overcome. I suppose we could model that as half of the penalties for swinging weapons, but there has to be something to make up for that resistance.

Originally Posted by davidtmoore

-1 to skill (can be bought off with a perk, "Aquatic Combat", specialised in the skill) and skill cannot exceed Swimming skill; Aquatic and Amphibious characters disregard both penalty and limitation.

Amendment: Swimming floated to DX.

Originally Posted by davidtmoore

Unarmed attacks, Close Combat weapons and all thrusting weapons:
+2 to target's dodge (can be reduced with Deceptive Attack)
-2 to damage, or -1 damage per die, whichever is worse.

Swinging weapons with a reach up to attacker's SM+1
+4 to target's dodge (can be reduced with Deceptive Attack)
-3 to damage, or -2 damage per die, whichever is worse.

Note that 1/3 would translate to -2 per die, and 1/2 would translate to -3 per die.

Originally Posted by davidtmoore

Swinging weapons with a reach of attacker's SM+2 or higher cannot be effectively used underwater.

Hrm. For mere mortals, this rings true; for Namor smacking Attuma with a sunken ship, not so much. But this is flavor, mostly. Perhaps this would make for an Optional Realistic Rule.

Originally Posted by davidtmoore

Okay, although I would tend away from automatically making being underwater a mitigator for near-sightedness. I might suggest that a player who wants his character to be able to see clearly underwater take Nearsightedness with a mitigator: Except underwater, and Nictating Membrane.

Originally Posted by Anthony

Yes, while it may possible for water to randomly give the exact correction needed for good vision, it's very unlikely. Also, my personal experience is that underwater vision (without goggles) is blurry at all ranges, not either near or far sighted.

Ah, well, I was afraid that little snippet might not survive too much scrutiny. Instead, how about combining the penalties for Near- and Farsightedness?

Vision and Visibility: -6 to Vision rolls, -3 to DX on close manual tasks (including Close Combat), and -2 to melee attacks; double actual distance to target when calculating range penalties. Mitigated by goggles, diving mask, or Nictating Membrane.

Originally Posted by davidtmoore

Also I note that Explosives: Demolition and Explosives: Underwater Demolition default to each other at -2, so I would regard this as a pretty minor penalty most of the time.

Well spotted! Let's change the Default to Prerequisite skill-2 and call it a wash.

Originally Posted by davidtmoore

Knockback is always halved underwater.

Originally Posted by davidtmoore

Scratch that; call it 1/5, like Swimming speed.

Interesting! I'm definitely sold on the first one, and I think I see the reasoning on the latter one. Let's see if we can stir up some more commentary and then I'll add one or the other.

Many thanks to Crakkerjakk, davidtmoore, and Anthony. I'll edit the top post when I get a moment. Keep the ideas flowing.

[davidtmoore]

Originally Posted by Erik_Nielsen

These are both very interesting ideas. The feeling I get for Dodge from the Forums is that it includes any kind of twisting, turning, ducking, or weaving to get out of the way of something about to hit you. While I agree that there ought to be a penalty, reducing Dodge to Swimming Move + 3 would be murder on any normal human (since, after all, the most Swimming Move JQMortal is likely to have is 3 [ (Basic Move / 5) + 2 max], so we're talking a maximum Dodge of 6 for any humans in the water).

I propose, instead, a penalty of -3 (not as severe as, say, being Stunned, but still pretty penalizing). That way, your Ninja, with her usual 15- Dodge, can twist out of the way of Bondo-san's spear gun on a 12-, whereas Warez Wally, Bondo-san's bumbling sidekick, is still stuck with a 5-.

Thoughts on a happy medium?

This is why I want underwater attacks to provide the target with a bonus to dodge. A strong swimmer with a BS of, say, 6.25 might have a land Dodge of 9 and swimming Dodge of 5. But the evil merman's trident thrust gives him a +2 to Dodge (as below), so he's dodging at 7. He can Retreat on that bad boy as well, giving him a final Dodge of 8, which is pretty respectable. In fact, he probably has Aquabatics, so can attempt an Aquabatic Dodge to boot. The merman's dodging the swimmer's own attacks at 11, but then, you probably shouldn't throw down with a merman in his own environment.

The ninja with a land Dodge of 15 presumably has a high BS anyway, and a number of skill and conditional modifiers, all of which would be applied to the swimming Dodge as much as the land Dodge.

Thoughts:

- Perhaps raise the limit slightly, to the lower of BS or Swimming Move+1 or +2, or double Swimming Move? But I would tend to disagree with that.
- Ooh! Or raise the limit by one if the PC has learned Swimming to HT+1, and by two if he has learned it to HT+2?
- Allow a wetsuit and flippers to give the character the Amphibious advantage, thus negating all the penalties.

Originally Posted by Erik_Nielsen

This is reasonable to me. Perhaps we could expand it to include Evaluate, Aim, and Concentrate, since these are non-active maneuvers. I don't recommend including Ready, since it already implies some kind of movement.

I heartily concur. I'd already noted that in my document on this subject.

Originally Posted by Erik_Nielsen

By "bonus to target's dodge," do you mean like the +2 to defenses for Telegraphic Attack [MA113]? That's an interesting way to get around the drag effect on swung weapons. That said, drag is a serious factor both on damage and accuracy; I do not feel comfortable simply doing away with to-hit penalties, although I could be talked into reducing them, especially with the dodge bonuses. Perhaps a -2 for swinging weapons?

Drag should slow but not necessarily deflect movement, although I can see that eddies and current might. To some extent, though, I see that as something a skilled fighter can be aware of and compensate for.

I could accept a -2 for swinging weapons.

Originally Posted by Erik_Nielsen

For thrusting weapons, I've seen a significant bend when attempting to use a spear under water. Water resists significantly; you may think you're thrusting true, but there's a definite bias to overcome. I suppose we could model that as half of the penalties for swinging weapons, but there has to be something to make up for that resistance.

I'm partly motivated by a desire to encourage thrusting weapons; IRL, all fishing weapons thrust. Perhaps an optional rule to add a stronger penalty based on current?

Originally Posted by Erik_Nielsen

Amendment: Swimming floated to DX.

Good catch.

Originally Posted by Erik_Nielsen

Note that 1/3 would translate to -2 per die, and 1/2 would translate to -3 per die.

Not so! An average die is worth 3.5, not 6. A penalty of -1 is just under 1/3 and -2 is over a half.

Originally Posted by Erik_Nielsen

Hrm. For mere mortals, this rings true; for Namor smacking Attuma with a sunken ship, not so much. But this is flavor, mostly. Perhaps this would make for an Optional Realistic Rule.

I think mere mortals are more likely to be using these rules than Namor. It might be worth stating that in Cinematic or Supers combat, the GM can allow Aquatic/Amphibious characters to ignore all effects of fighting under water.

Originally Posted by Erik_Nielsen

Ah, well, I was afraid that little snippet might not survive too much scrutiny. Instead, how about combining the penalties for Near- and Farsightedness?

Vision and Visibility: -6 to Vision rolls, -3 to DX on close manual tasks (including Close Combat), and -2 to melee attacks; double actual distance to target when calculating range penalties. Mitigated by goggles, diving mask, or Nictating Membrane.

...Aquatic or Amphibious. Might also be worth allowing a Perk: Underwater Vision (like Nictating Membrane without the HT bonus) and a Feature (for the Machine meta-trait, etc.)

Originally Posted by Erik_Nielsen

Well spotted! Let's change the Default to Prerequisite skill-2 and call it a wash.

Agreed. With a per-skill Perk to cancel the penalty, except for Demolitions.

Originally Posted by Erik_Nielsen

Interesting! I'm definitely sold on the first one, and I think I see the reasoning on the latter one. Let's see if we can stir up some more commentary and then I'll add one or the other.

Many thanks to Crakkerjakk, davidtmoore, and Anthony. I'll edit the top post when I get a moment. Keep the ideas flowing.

Any thoughts on the Nets-at-range-0-or-1 idea?