Games

Osmose, a tactical RPG

A turn-based tactical RPG in the style of Dofus, written from scratch: a Godot 4 C# client for Windows, macOS and Linux, rules shared with an ASP.NET Core server for accounts and characters, a launcher in Rust.

In progress Sprint S45-S60+S64-S219 · 728 points

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What it is: A turn-based combat video game on a board seen at an angle, like Dofus: you create your character, walk around a town and talk to its people.
What it is for: A real game to download, with its installer, player accounts and a server, built to grow: monsters, landscapes, then multiplayer.
What it shows: Running a large video game project, from its rules to its distribution, in C# and Rust.

Source code

How the pieces fit together

The launcher (Rust, Tauri) signs the player in, compares the installed game with the server's manifest (size and SHA-256 of every file), downloads only what changed, resumes a cut download, checks every file, then starts the game with the token.
The desktop game (Godot 4, C#) only draws: login screen, village, fight. Everything a click can do lives in Rpg.Client, a library without an engine tested with xUnit, which the game replays itself in the CI (self-tests).
Rpg.Core holds the rules and the data (spells, classes, monsters, maps, village, dialogues): the same library serves the game, the server and the simulator, so a recorded fight replays identically everywhere, on all three systems.
The server (ASP.NET Core) handles accounts and characters (JWT, hashed passwords, rate limit, EF Core and PostgreSQL), checks every request with the rules of Rpg.Core, and serves the game's files to the launcher.
Rpg.Sim, the command-line simulator, has the AI play thousands of times: it is what balanced the classes and the monsters.

A look at the fight

The desktop client, in Godot 4 and C#: a diamond board seen at an angle, animated characters (Kenney's free 3D models), and the rules of sprint 45, without a single extra rule in the client.

A 36-second video, without sound, recorded by the game itself: a training fight where the AI also plays the heroine. She walks up to the orc and the poacher and strikes them up close; hit points drop above their heads, the log on the left tells every blow, and she wins narrowly in round six, with 6 HP out of 60.

The launcher's window: at the top, the village of Clairval as a banner under the name "Osmose" and the FR button; below, the "Account name" and "Password" fields, the "Remember the account name" and "Remember the password" boxes, the "Sign in" button and the "No account yet? Create one" link; at the bottom, the update bar, full, and "Game updated (version 1.0.10, 196.9 MB)". — The launcher (Rust, Tauri): it updates the game by itself when it opens, file by file; "Sign in" starts the game; the name and the password can be remembered (the password in the system's credential store). Windows, macOS and Linux packages made by the CI, unsigned.

The game's characters screen, on the server Osméria, in front of the darkened village of Clairval: three cards, Ondine (Sentinel, level 1, red hair), Élise (Mage, level 1, blue hair, framed in pistachio: she is the one chosen) and Bastien (Guard, level 1, tall and broad, dark skin), each with a 3D portrait, then a "+ Create a character" card; below, the "Play" and "Delete" buttons. — After the launcher, as in the games of the genre: the server choice (straight through while there is only one, Osméria), then the characters as cards (portrait, class, level), up to five per account. Accounts and characters live on the server (ASP.NET Core, PostgreSQL).

The creation screen, in front of the darkened village: on the left, the character turning, the "Woman" (chosen) and "Man" buttons and the six women's looks as thumbnails, "Woman B" framed; on the right, the class (Sentinel, Guard chosen, Mage), its description with its points and elements (Earth, Fire), then its twenty spells by unlocking level, from level 1 to level 100, the colour swatches of outfit, hair and skin, the height and build sliders, the name field "Aubépine" and the "Create" and "Cancel" buttons. — Creating one's character: class (with its twenty spells, by level), woman or man then one of six looks, outfit, hair and skin colours, height and build, on Kenney's free models; each swatch shows the colour it will give this model. The server checks every value.

The village of Clairval seen at an angle: four houses with pointed roofs, a fountain in the middle of paved roads, fir trees, a pond, two market stalls. The player has walked up to Aubin, in the middle, whom the camera follows: only his name shows, the inhabitants further away (Rose by her stall, Garance next to the east gate marked with a red ring and the text "East gate: training") stay nameless. At the top, a pistachio green ring and the text "West: Clairval Woods". At the bottom, the talk: "Aubin", his line about MP and AP, and two numbered answers. — The welcome town: you walk with a click, talk to three inhabitants (dialogues with choices, described in data), the east gate leads to a training fight, the west road to Clairval Woods; the server keeps where the character stands.

Clairval Woods seen at an angle: a white paved road winding between rows of fir trees, rocks, a pond. The player stands in the middle of the screen, on the road, next to a pistachio green ring and the text "North: Misty Heath"; further left, a red ring and the text "Glade: training". At the top left, "Clairval Woods" and the help "Click: walk · click on someone: talk to them · wheel: zoom · Q and E: turn · M: map"; at the top right, the "Map" and "FR" buttons. — A level-3 zone, twice the size of the village: the camera follows the player, zooms with the wheel and turns a quarter with Q and E; the green ring leads to the next zone, and the server keeps the zone and the cell one stands on.

The world map, open over Clairval Woods: three boxes joined by lines, "Misty Heath, level 10" at the top, "Clairval Woods, level 3, you are here", outlined in pistachio green, at the bottom left, and "Clairval, level 1" to its right. — The world map (M key): each zone in its place, with its level, joined to its neighbours; the zones and their links are described in data and checked by the tests.

The characteristics sheet, over the village: at the top, Aubépine's portrait, "Level 10 · Guard" and the "Characteristics" and "Spells" tabs. On the left, tiles: Hit points 122, AP 8, MP 4, Initiative 10, Points to spend 6 / 90, and a "Reset" button. On the right, a table, each row in the colour of its element: Vitality (pink) 20 put in, +5 from equipment, 25 in all, +25 HP; Earth (brown) 45, +20, 65, +12 Earth damage; Fire (red) 0; Water (blue) 9, +4, 13, +2 Water damage; Air (green) 10, +4, 14, +2 Air damage; a resistance column at 0%, then MIN, minus, plus and MAX buttons. Below: "10 points in an element = +2 damage in that element, and nothing else". — The characteristics sheet: Vitality, Earth, Water, Fire, Air, each in its colour; the points put in and those of the equipment, what each total gives (10 points = +2 damage in the element, and nothing else); a value to type, MIN, MAX, and everything taken back at any time.

The "Spells" tab of the character sheet: at the top, filters All, Neutral, Earth, Fire, Water, Air and "Spells: 8 spell point(s)". On the left, a grid of tiles, each with its white icon on the colour of the spell's element: Shield Bash (rank 2/5, in the deck), Burning Blade, Ice Blade, Slash, Taunt, Bulwark, Cleave (all in the deck), then greyed spells with their level (Fire Lunge lv 15, Undertow lv 20…); below, "Deck 7/12" and the deck's seven icons. On the right, Shield Bash's card with its icon: rank 2/5, Earth, cost 3 AP, range 1 to 1, 2 casts per turn, critical 10%, "20 to 24 Earth damage" in colour, "22 to 26 on a critical hit" in bold, push by 2, next rank for 2 spell points: 22 to 26, a "Take out of the deck" button and minus and plus buttons. — Spells: the class's twenty-four, four per element and eight neutral, each with its icon on its element's colour, locked until their level; the card gives normal and critical damage with the character's characteristics and equipment, and what the next rank gives.

The inventory and equipment screen, over the village: on the left, the character in 3D between two columns of seven square slots (hat, amulet, cape, pauldrons, breastplate, belt, boots; rings 1 and 2, one-handed weapon, two-handed weapon, shield, pet, mount), each showing the icon of the item worn or, faint, the shape of the empty slot. On the right, a "Search for an item" field, the All, Equipment, Consumables, Resources and Quest tabs, and a grid of drawn icons (ring, sword, paw, cape, boots, potions, fangs, badge), in the colour of their characteristic, with their count; below, a frame giving the card of the item under the mouse; at the bottom, "Save" and "Close". — Gearing up: the character surrounded by its fourteen slots, the inventory in tabs and a grid, a search; the icons are drawn by the game (the shape says the slot, the colour the characteristic). A sample inventory of a level-10 guard; in the game, the server keeps what each fight leaves.

Isometric grass board, chequered, with trees, rocks and two ponds; Aubépine, a tenth-level sentinel, at the top left, an orc and a poacher ringed in red on the right. The cells she can reach are light green, the path to the cell under the mouse yellow. At the top, "Round 1 · Your turn" and, on the right, the timeline of the next eight turns as portraits; on the left, the log (the poacher and the orc moved). At the bottom, HP 111/111, AP 8, MP 4, then the deck in two rows of six: seven spells, each with its white icon on its element's colour (brown, red, blue, green, grey), numbered 1 to 6 then Ctrl+1, the last five places empty; then the "End turn" button. — Moving: the reachable cells, the path, and the deck of twelve spells in two rows (keys 1 to 6 and Ctrl+1 to 6).

The same fight: Burning Arrow (second place of the deck, outlined in pistachio) is chosen; the cells within its range are marked and the poacher, aimed at, stands on a red cell; on the right, under the timeline, the hover panel says "Poacher: 17 to 20 damage, 19 to 22 on a critical hit" above its card "Poacher · 44/44 HP · 6 AP · 4 MP". At the bottom, HP 111/111, AP 8, MP 1, and the sentinel's deck with its icons. — Aiming: the spell's range, the line of sight, the target and the damage to expect, critical hits included; at the top, the timeline of the next turns.

Pictures taken by the game itself (option --screenshot), in a virtual screen, with Mesa's software OpenGL renderer.

Spell icons: game-icons.net, under the CC BY 3.0 licence, by Lorc, Delapouite and Sbed (background removed, set on the element's colour).

To run it at home (.NET 10 SDK and Godot 4.7 .NET):

cd projects/rpg
dotnet run --project src/Rpg.Sim -- --simulate 100 --lang en   # AI fights, in the terminal
docker compose up --build rpg-api                                   # the accounts and characters server, on port 8002
dotnet build godot/Rpg.Godot.csproj
godot --path godot -- --lang en                                # the game ("Play offline" without a server)

Ready-to-run builds (Windows, macOS, Linux, unsigned), made by the CI, which plays a whole fight in them, kept 14 days: artifacts of the rpg workflow

Tech stack

Godot 4
C#
.NET
ASP.NET Core
EF Core
PostgreSQL
JWT
Rust
Tauri
xUnit
Docker

Who does what

Godot 4: The desktop client: isometric maps, combat, character creation, town and NPCs, exported for Windows, Linux and macOS by CI.
C#: The game rules (grid, action and movement points, line of sight, spells, AI) in a deterministic library, shared by the client and the server.
.NET: The common platform of the client, the rules and the server.
ASP.NET Core: The accounts and characters server, which validates every character created.
EF Core: Database access and its migrations.
PostgreSQL: Accounts, characters and their progress.
JWT: The login tokens, shared by the launcher and the game.
Rust: The launcher: login, checking and downloading only the changed files.
Tauri: The launcher's interface and its packages for the three systems.
xUnit: Tests of the rules (paths, line of sight, replayed fights) and of the server, on a real PostgreSQL database.
Docker: The server and its database, started by docker compose.

Definition of Done

Code reviewed, diff by diff
Unit and integration tests green
Green CI on Linux, Windows and macOS when compiled
README, REVIEW.md and DECISIONS.md up to date
Texts in French and English
Demo deployed and tested on mobile