Goodman Games

In an upcoming session my players are going to be fighting something underwater. I have some ideas sketched out on how to handle this, but wanted feedback.

The world implied by the core rulebook is probably one in which most people can't swim and would only be a trained skill to those with the relevant occupation. However, it's already going to be hard enough to fight a Leviathan underwater so I am fine saying that all characters (levels 4-5) have the ability to roll this trained under the notion that they are capable of heroic feats at this point.

Swimming

When characters enter the water they must make a Swimming check (1d20 + Str Mod). This allows them to make a single movement and maintain position afterwards.

The base DC is 10, which allows them to take a normal action but they receive no Agility bonus to their AC.

Characters who roll 15+ get their Agility modifier to AC.

Moving will require another check, which uses an action die.

Failure means the character cannot move or maintain position but spends the round flailing wildly.

If a character rolls a natural 1 on their swim check, they begin Drowning (see below).

Drowning

Characters can hold their breath for a number of rounds equal to their Stamina score divided by 2 (ie, a character with 10 stamina has 5 rounds before they begin drowning).

Characters who are drowning suffer 1dX damage/round where X is equal to their Hit Die.

Characters who are drowning cannot attempt any action and also count as withdrawing from the combat as they begin sinking to the bottom of the sea.

Spellcasting Underwater

It is still possible, but is done at -1d on the die chain due to the muddying of speech and movement being less agile. Additionally, any turn in which a character casts a spell advances counts as two rounds for the purposes of tracking when they begin drowning.

Thoughts?

Looks pretty good. I definitely like the choice of move or act.

I'm not sure how much movement you're allowing with a success. Personally, I be tempted to let the roll determine that: every point above the DC is a foot of movement (this could be adjusted by the state of the water, i.e., very calm waters might allow for more movement, severely choppy waters, less).

Tower of the Black Pearl allows for folks to hold their breath for a number of rounds equal to their Stamina score, and taking an action uses up two rounds worth of this on that round, which I like.

Three thoughts:

1) If my players tried to tell me their characters can swim just because they're level 5, I'd say no way. Swimming really is a trained skill, and unless they had a water-oriented patron or something like that, I don't see a way around "swimming lessons" before they can do it.

2) Your "swimming check" system for movement looks pretty good.

3) Moving underwater is one thing, but attacking is quite another, particularly against aquatic creatures who are going to be much more agile in that setting than are land-based creatures (like the PCs). Also, landing attacks other than stabbing-type puncture wounds with a pointed-tip blade or pole should be done at huge penalties. For example, imagine swinging a battleaxe or longsword underwater. You can't get any real speed/force to inflict damage going even if you do manage to make contact with it.

In this case, they've been at sea before and have definitely swam as well. Basically, I'm willing to suspend some of the ways I would normally work so not immediately destroy them as this is the first encounter of a series of encounters in the final dungeon.

Good point on the damage - all attacks and damage are done at -1d on the chain unless the are piecing.

Vanguard wrote:In this case, they've been at sea before and have definitely swam as well. Basically, I'm willing to suspend some of the ways I would normally work so not immediately destroy them as this is the first encounter of a series of encounters in the final dungeon.

Good point on the damage - all attacks and damage are done at -1d on the chain unless the are piecing.

I would honestly go more than -1d. Try swinging a baseball bat underwater. No comparison to swinging one in air. Slings would obviously also be totally useless, and I'm not sure how bows would work.