Better Rules for Maritime Adventures

To be brutally honest, I don't think I've ever read any OSR/NSR rules for naval combat and seafaring turns that didn't feel like a) they belonged in an ancient wargame or b) the designer's heart just wasn't in it, and they just wanted to get over and done with that part of the game as soon as possible. And as a fan of vikings and pirates, I always felt like this was such a disservice to something that could be just as fun as regular overland travel or dungeon exploration, both of which have been done superbly in several OSR/NSR games. 

The great thing about the OSR and the NSR alike (I'm still trying to figure out whether there really is a need for such a distinction, but I digress), though, is that when something hasn't been made yet, there's this strong encouragement to go ahead and do it yourself. So I went and did exactly that. Now, the title is presumptuous as hell, I know, but I really do believe these rules are pretty cool. They were heavily inspired by classic dungeon crawling procedures (such as OSE's) and by Apocalypse World 2e's vehicle rules and moves — a weird combination, for sure, but then again, most of my stuff is a mix of classic OSR and PbtA anyway. 

Time to dive in, mateys.

BUILDING YOUR SHIP

All seafaring vessels are described through the following attributes: Size, Speed, Handling and Hull. By default, every vessel has a score of 0 in these attributes. A ship’s Size category also affords it with a number of Armaments and Improvements, as seen below.

Size 0: Boats or rafts, for example. 1 Improvement, no Armaments.
Size 1: Small longships or sailing ships. 2 Improvements, 1 Armament.
Size 2: Transport ships or small galleys. 3 Improvements, 1 Armament.
Size 3: Large longships or sailing ships. 4 Improvements, 2 Armaments.
Size 4: Large warships or large galleys. 4 Improvements, 3 Armaments.
Size 5: Heavy warships or longships. 5 Improvements, 3 Armaments.

Any ship larger than Size 5 gets +1 Armaments for each number above that. Armaments can always be traded for further Improvements, and vice-versa.

Improvements are used to increase the ship’s attributes (except Size). Aside from its use in naval actions, Speed is also factored as an abstraction of how many hexes (or how many increments of 6mi) a vessel can cross in a day. Much the same way, Hull can be used as an abstraction for the ship’s maximum number of passengers and its cargo limit, with each point of Hull counting as 10 to 50 passengers (crew included) and 20 to 100 tons at most.

For the purposes of naval combat, Size counts as Hit Dice and should be rolled to determine the ship’s Hit Protection. Armaments start at d6 damage, but one can spend an Improvement point to increase that damage by a step. Speed is used to determine combat Initiative, and ships with the same Speed rating act simultaneously. Speed can also be used to determine the amount of squares a ship can cross in a combat grid per turn, if one is being used.

NAVAL ACTIONS

There are a number of actions a ship’s crew can take during their turns at sea. These actions can be undertaken by any member of the crew, but it is a good idea to assign functions among the party, such as captain, boarding leader, navigator, engineer and quartermaster.

• Undertake a journey: For each six miles of travel, the crew should make the following checks: Dexterity, to deftly keeping their ship on the right path, Wisdom, to properly determine what path that is, and Charisma, to keep all spirits high.

Failing any of these checks results in a 2 in 6 chance of triggering an encounter (DEX or WIS) or an event (CHA). In addition, failing the Dexterity check also halves the distance traveled, while failing the Wisdom check has a 2 in 6 risk of leading the ship the wrong way (roll a d6 to determine direction: 1. north, 2. northeast, 3. southeast, 4. south, 5. southwest, 6. northwest). 

Encounters should be rolled on an appropriate maritime encounters table, while events function much like a normal encounter, but with a table of situations pertaining only to the ship’s crew and their circumstances.
 

• Navigate perilous seas: In order to safely navigate troubled waters or obstacles, a crew member must roll under either their Dexterity or Wisdom, whichever is higher. They subtract the ship’s Handling from the result.
 

• Attack: When naval combat is initiated, the crew can make one attack for each of their Armaments. Crew members operating ballistic weapons must succeed at a Dexterity check, while ramming requires a Constitution check from the navigator in order to prevent their own ship from suffering any damage. Unconventional weapons such as Greek fire should trigger Wisdom checks. 

Although the brunt of the damage is always suffered by the ship itself, the enemy vessel’s crew always has a 2 in 6 chance of individually suffering half of the total damage dealt to their ship.
 

• Defensive maneuvers: When trying to avoid or minimize the effects of an enemy ship’s attacks, the navigator can check Dexterity to outmaneuver the attacks, or Constitution to bear the brunt of it. Succeeding at a Dexterity check ignores the damage entirely, while succeeding at a Constitution check halves it and eliminates the possibility of damage spillover to the crew (2 in 6 chance of individually suffering half of the total damage received by the ship, as above).  

Defensive maneuvers can also be used to avoid boarding. To do this, the navigator must pass a Dexterity check.

• Board: All it takes to board a ship is being close enough to it and passing a Dexterity check (done by the navigator). Once a ship is boarded by a crew, maritime adventure rules cease to be the focus, being replaced by regular combat procedures in the case of a fight or by a diplomacy challenge.

• Emergency repairs: When plugging holes, tying ropes or putting out fires, a crew member can check Intelligence to devise a workaround for the ship’s current maladies. Succeeding at that check restores d8 HP to the ship.

• Overtake & outdistance: When trying to overtake or outdistance a ship or sea creature outside naval combat, the navigator checks Dexterity if relying on their vessel’s Speed, or Wisdom if betting on its Handling. They subtract either Speed or Handling from the result.

SAMPLE SHIPS

Below are some examples of ships built with these rules.

• Skeid longship

Size: 3
Speed: 2
Handling: 1
Hull: 2 (45 passengers, 80 tons at most)
Hit Protection: 17 (3 HD)
Armaments: Archers (d6), spearmen (d6), ram (d6)

• Man-o'-war

Size: 5
Speed: 1
Handling: 2
Hull: 3 (200 passengers, 300 tons at most)
Hit Protection: 28 (5 HD)
Armaments: Heavy ballista (d8), light ballista (d6), ram (d6)

• Trading cog

Size: 2
Speed: 2
Handling: 1
Hull: 2 (60 passengers, 240 tons at most)
Hit Protection: 10 (2 HD)
Armaments: Archers (d6)

ON ABSTRACTIONS

There are a lot of abstractions here, and that's intended. Personally, I feel like trying to simulate the exact speed with which a ship travels in a good or bad day is a losing battle. There are just too many variables, and rather than making the game feel grounded, this just grinds it to a halt. At the end of the day, those "exact" measurements are still abstractions. They're just crunchier and less intuitive than they need to be, oftentimes for the sake of appearing realistic.

And with that said, I'll leave y'all with an epiphany I had while writing this post: these rules can be just as easily used for airships, with little to no adjustments.

Fair winds and following seas to all!