Game thinking from Adam Clare

Tag: Declaration of Paris

Scapa Flow: My #1GAM WWI Submarine Game

For my April one game a month challenge I “finished” my submarine game. Finished is in quotes because there are still things I want to improve but it’s playable. It’s unlike other submarine games in the sense that there are no battle tactics, only conversational tactics. And unlike the last post on this game, it now has a title: Scapa Flow.

Scapa Flow

Scapa Flow is a body of water in the Orkney Islands, Scotland which served as a base for the British Grand Fleet during both World Wars. The base closed in 1956 with only three known u-boat incursions. The title of the game alludes to the frustrations on both sides of the war: the English feared u-boat infiltration and the Germans knew that successfully attacking Scapa Flow was a pipe dream.

I have previously written about some of the design rationale. This post is about the current state of the game.

If you want to play the game please contact me as it’s in private beta right now.

Scapa Flow Gameplay

The player takes on the role of commanding a German U-boat during the First World War. They navigate open waters near a coast with relatively heavy shipping and protection from the British Royal Navy. The goal is to sink British ships while not getting caught, you can be caught by engaging with a civilian ship giving away your location or a British ship finding you.


Scapa Flow is set before February 1915 when the Germans announced that they were engaging in unrestricted submarine warfare. Which means that the player needs to discern which is an enemy combatant ship and which isn’t. There is only one clear way of doing this in the game as some civilian-looking ships are actually Royal Navy ships. The way to figure out foe from anyone else is to use radio.

The use of radio in the Great War was amateur at best because of the newness of the technology and a lack of training on how to use it. In the game, I made it so the only use of radio is for conversations with nearby ships. This may be a bit of a stretch but it gives the player agency beyond guessing. If you’re interested in learning more about radio at this time you can read Wireless Waves in the World’s War.

There is no clear way to win the game and that is on purpose. In Scapa Flow game, even if you “win” by sinking enemy ships you’re not rewarded for it. The only thing that permits the player to keep playing is to not bring the Declaration of Paris – which is harder than you think!

The goal of the game is to point out the rules of engagement that were used in the early stages of the Great War. When talking about the early land war I often find people reference cavalry charges against tanks (which is a myth and not even during WW1); however, there is truth to the claim that generals were having to relearn how to fight. New technology and powerful weapons literally change the shape of the battlefield. Having to adjust to new techniques was not isolated to just land battles – it extended to sea battles too.

At the start of the war the British and French destroyed German surface shipping. Britain had the largest navy at the time and the Germans were considered quite weak. So, the Germans were essentially blockaded – except for their u-boats. Now the tides had turned and the weaker naval force could cause considerable damage.

The Germans were able to sink Royal Navy ships but they also wanted to stop war material shipping. This posed a problem of whether or not naval warfare ought to follow the ‘old’ rules of the sea. That means military ships should only attack other military ships and not attack civilians – as that would be considered piracy. At first, the Germans followed the anti-piracy rules known as the Declaration of Paris.

Captains were supposed to message merchant ships, let them know you’re searching their ship. Then, if something is found, let the crew evacuate the ship. Thus leaving the ship to be scuttled or taken as a prize. The problem with all of this, is that u-boats need to surface to do so.

A surfaced submarine is vulnerable. The British (knowing that the Germans were following the prize rules) started putting hidden guns on merchant ships so when a u-boat surfaced near a merchant ship the u-boat was vulnerable and could be attacked.


The Germans were told that if they used their u-boats to target merchants that the USA would enter the war. America entering the war so early would increase the probability that the Germans would lose the war and lose access to the material the Americans were selling to both sides.

All this time, the French and British submarines were sitting essentially idle at dock with nothing to shoot at.

Nobody wins in the Great War, one side just lost less.

Designing the game:

Like other months, I create some design goals or challenges for myself. As always, there are technical limits (or new tools) I place on myself and thematic tasks too. This time around I had two technically related choices set out for myself:

On the thematic side, I wanted to explore making a serious game that had a short gameplay experience which could encourage a class discussion. This worked out quite well for a game built starting at a jam as the scope wasn’t insane.

As you can gather from the above description of the game play I likely went too far in scope. At the same time, it’s a short and simple game. It took some time to get back up to speed on some Unity things but once I did, everything started to progress at an OK rate.

Using Unity was a good decision, and most of the games I make for the rest of the year will be in Unity (That being said, my next game uses GameSalad).

I should have been able to do all of this in C#, instead I decided to use PlayMaker and I’m not sure it made things easier.



Playmaker is a visual editing tool that is designed for people who aren’t familiar with programming. At first I was pretty impressed by it as it’s obvious that one can build an entire game using PlayMaker. By the end of working on Scapa Flow I found it frustrating. The reason for this is less PlayMaker than it is me starting to learn C#.

If you are planing on making a game using PlayMaker I suggest that you use only PlayMaker and to not try to integrate text-based scripting with it. Another thing to keep an eye on is how you use the scripting on game objects in Unity. I decided to create a camera controller script separate from the conversations players have with ships and this ended up being more trouble than it was worth. If I was to do this again, I would structure the game objects in a more logical way for PlayMaker whereas the structure I used makes sense for non-visual scripting.

Next steps:

To be honest, there are still some bugs in the game which I’m squashing as I work on May’s game. Keeping up with getting a game a month completed is harder than I predicted (no shock there) and I’m hoping that I’ll be able to get back on pace soon. Still, some progress is better than no progress.

Regardless, I may need to decrease my scope for the rest of the year’s projects.

From an earlier version of the game showing the periscope view.

From an earlier version of the game showing the periscope view.

Here’s a rundown of what I want to do with the game before making a big release:

  • More play testing
  • Finish accompanying lesson plan
  • Fix minor game bugs
  • Add more conversation branches
  • Get it working on tablets (maybe)

Once those are complete I’ll put the final game out in the wild.

As with many recent projects, I must thank Ali for a whole bunch of help.

My previous #1GAM games:

January – Gnome Oppressor
February – Village of Cards
March – AstroDoge

Jamming Submarines: On Creating A World War One U-Boat Game

In lieu of TOJam happening this coming weekend I wanted to look back at my last jam-made game.

Submarine game

Got to love early builds!

During the last weekend of January thousands around the world, participated in Global Game Jam. I was one of those people. As a design constraint for myself I opted to make an educational game about water in an historical or environmental context (all topics I obviously care about). 45 minutes before the jam began I decided to make a game about history – specifically a game focused on World War I naval combat.

If you’re in the Toronto area you should come on out to the Toronto Global Game Jam Arcade at Bento Miso May 3rd.

Why World War The First?

I’ve studied quite a bit about the Great War in my undergrad years; although most of that time studying I was focused on the political, personal, and the cultural ramifications of the war. Why not explore the gaps in my knowledge by making a game?

I’ve been conceptualizing a trench-focused game for some time and want to release it later this year. The trench game is meant to highlight the hardships and constant death of what unfolded on land, which is something I do know about. Fortunately I don’t know this from firsthand knowledge.

With all of this in mind I wanted to push my knowledge of the Great War through game design. I’ve also never made a game set on or in water, and I have to say the water we “made” is gorgeous.

Submarine game 3

Here we follow a torpedo en route to hit a ship (note the lack of textures on the ship).

What’s more, by making a game about u-boats in this war opposed to the better-known u-boat campaign of WWII it would save us time and effort. This was before the militaristic use of the radio and the advent of both radar and sonar (no need to build those in code). There was a smaller number of torpedoes that a sub could carry. To cap it all off, WWI was filled with really bizarre (to our modern world) notions of how to engage in combat.

Here’s a primer on how the Germans fought using their U-boats:

The Game

Luckily (for me) Ali’s team couldn’t make it, so the two of us joined forces. We got our game to a playable state during the jam and have worked on it since.

I thought it would be worthwhile to record some of the historical research and initial game design.

The game has the player taking on the roll of a German u-boat captain in the early stages of the war; which is before unrestricted submarine warfare was declared by the Germans in February 1915. As a result, it’s important to follow the rules of engagement of merchant vessels:

Part IV, Art. 22 of the Treaty for the Limitation and Reduction of Naval Armaments, relates to submarine warfare. It states as follows:[2]
In their action with regard to merchant ships, submarines must conform to the rules of international law to which surface vessels are subject.
In particular, except in the case of persistent refusal to stop on being duly summoned, or of active resistance to visit or search, a warship, whether surface vessel or submarine, may not sink or render incapable of navigation a merchant vessel without having first placed passengers, crew and ship’s papers in a place of safety. For this purpose the ship’s boats are not regarded as a place of safety unless the safety of the passengers and crew is assured, in the existing sea and weather conditions, by the proximity of land, or the presence of another vessel which is in a position to take them on board.

Which essentially means that a warship (in our case a u-boat) can stop a merchant vessel and search it. If war materiel is discovered then the warship can do one of three things:

  1. Take the ship and contents as a prize;
  2. Sink the ship providing the crew is safe in their lifeboats;
  3. Let the ship go.

The third option is not a viable option in most cases, and the first one is particularly hard for a submarine to accomplish. Within a u-boat There is no storage room to carry a crew just for the potentiality of capturing a merchant ship. Meaning that the only real option was to sink the ship.

It was here that the unique gameplay can be found. The player needs to balance the goals of the war (kill/stop the opponent) while following international piracy laws.

Essentially, the player cannot go around just shooting any ship they find; it’s a risk to just fire at any old ship. This means that the game has two parts to it: hunting and talking.

Submarine game 2

The buttons allow one to talk, fire, or return to hunting.


This part is what it says on the tin: the player explores the water (or lays in wait) to find a worthwhile target. There are multiple clues to figure out if a ship is part of the Royal Navy or if it’s a merchant ship.

The key to hunting is not to be seen. If the player outs themselves by speaking to a ship that can reveal their location….well, bad things happen to the player.


Once a player targets a ship they can choose to attack at anytime or try to maintain a conversation. It is possible that a ship the player thinks is civilian is just lying and will turn around for the kill. Considering the timing of our game, during the blockade of Germany, once the u-boat is identified by non-German ships their is no escape for the player.

Optional Gameplay to Add

I am not sure we will ever add these but thought I’d bring them up anyway. We’ll see what the reaction is at the TGGJ arcade.

The first element that is needed is better artificial intelligence for the ships. Due to time constraints we don’t have an AI system which would have the Royal Navy warships self-identify and hunt the player. Currently, the only weapon in the game is the torpedo and we’d have to add ballistics and their trajectory if we’re going to have the Royal Navy hunt the player.

One thing that would be interesting is to have the player accidentally take out friendly merchants. This is not entirely unfeasible as Germany and Britain traded binoculars for rubber during the Great War. The problem is that the game is already somewhat frustrating when talking to captains who refuse to talk, and this could just add further confusion.

More knowledge:

The Paris Declaration

The Paris Declaration

This game is also an educational game and as such I’m creating a learning document to accompany the game. Here’s some of the research I did explicitly for this game, please note I’m also working on another Great War game and there’ll be another post with even more knowledge!

More about prize rules of the sea:
Declaration of Paris
Original copy of the declaration

To give an idea of scale and the difficulty in distinguishing merchant and naval ships here are some example of the types of ships which uboats were targeting:

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