D&D 5R: Water Movement & Combat

The 5E rules for aquatic encounters were smeared over a number of locations and generally left me with a lack of useful understanding.  The result was I avoided encounters in the water so I could avoid the puddle of rules that defined aquatic encounters.  

The 5R rules have made pretty big changes.  I'll dive into how it is defined to work in the newest iteration of the rules in this post.  As usual, I'll copy teh relevant rules snippets into this post, after I walk through what I think the rules mean to me and my games.

By the 5R rules, encounters underwater have a few major differences from normal situations:

1. Suffocation Risk
2. Movement Difficulty
3. Melee Attacks Impedded
4. Spell Casting (V)

I'll dive into to each below:

Suffocation Risk

5R RAW makes drowning in an encounter next to impossible.  Not breathing has a devestating effect but only after minutes for all but the lowest CON characters and they even get 5 combat turns before being affected.  Suffocation under water just isn't a thing by RAW.

Movement Difficulty

Moving underwater (e.g. swimming) is just movement in difficult terrain, unless a creature has a swim speed in which case it is normal.  

Melee Attacks Impeded

Melee attacks with a weapon are at disadvantage unless the attacker has a swim speed, -or- the weapon does piercing damage, in those cases the attack is normal.  Damage is normal in any case.

Ranged attacks with a weapon are at disadvantage while in normal range and not allowed beyond that.

Spell Casting (V) Affected?

Are spells affected?  RAW seems to leave this unaddressed, other that a clause in the silence spell that clearly states that spells with verbal components fail while affected by silence.  I'm inclined to extend this to say that V component spells fail underwater unless the caster has water-breathing.

Summary

Overall, water has relatively little effect on encounters in 5R.  The only area that I feel is ill defined is spell casting.  Also, suffocation not being a concern seems a missed opportunity, I'd rather like some kind of accelerator clause such that exertion brings about suffocation faster; however, house rules isn't what this post is about, so enough for now.

Rules Snippets

The rules for grappling are all tucked into the 5R Glossary Rules Definitions. 

Suffocation [Hazard]

A creature can hold its breath for a number of minutes equal to 1 plus its Constitution modifier (minimum of 30 seconds) before suffocation begins. When a creature runs out of breath or is choking, it gains 1 Exhaustion level at the end of each of its turns. When a creature can breathe again, it removes all levels of Exhaustion it gained from suffocating.

Thirty seconds is a LONG time in D&D combats.  Each turn is six seconds, meaning anyone can hold their breath for five (5!) turns of combat, plenty for the vast majority of combats.  A character with a 14 CON has a +2 modifier so they can hold their breath for 3 minutes or 30 turns of combat.   

So, suffocation is just not an issue for the vast majority of encounters.   

Swimming

While you’re swimming, each foot of movement costs 1 extra foot (2 extra feet in Difficult Terrain). You ignore this extra cost if you have a Swim Speed and use it to swim. At the DM’s option, moving any distance in rough water might require a successful DC 15 Strength (Athletics) check.

Swim Speed

A Swim Speed can be used to swim without expending the extra movement normally associated with swimming. See also “Swimming” and “Speed.” 

Underwater Combat

Impeded Weapons: When making a melee attack roll with a weapon underwater, a creature that lacks a Swim Speed has Disadvantage on the attack roll unless the weapon deals Piercing damage.

A ranged attack roll with a weapon underwater automatically misses a target beyond the weapon’s normal range, and the attack roll has Disadvantage against a target within normal range. 

Fire Resistance: Anything underwater has Resistance to Fire damage (explained in “Damage and Healing”).

Silence (Spell)

The silence spell includes the following which applies to a creature within the area of effect of the spell: Casting a spell that includes a Verbal component is impossible there.