diff --git a/client/src/App.tsx b/client/src/App.tsx
index 3c06cb9..cf2787b 100644
--- a/client/src/App.tsx
+++ b/client/src/App.tsx
@@ -16,7 +16,7 @@ function App() {
   const params = useParams();
   return (
     <div className="app">
-      <GameIdContext.Provider value={params.gameId}>
+      <GameIdContext.Provider value={"g/" + params.owner + "/" + params.repo}>
         <Outlet />
       </GameIdContext.Provider>
     </div>
diff --git a/client/src/LandingPage/index.html b/client/src/LandingPage/index.html
index f35abca..12c9882 100644
--- a/client/src/LandingPage/index.html
+++ b/client/src/LandingPage/index.html
@@ -23,7 +23,7 @@
 
     <div class="game-list">
 
-      <div class="game" onclick="location.href='#/game/adam';" style="cursor: pointer;">
+      <div class="game" onclick="location.href='#/g/hhu-adam/Robo';" style="cursor: pointer;">
         <div class="wrapper">
           <div class="title">Formaloversum</div>
           <div class="short-description">Erkunde das Leansche Universum mit deinem Robo,
@@ -66,7 +66,7 @@
         </table>
       </div>
 
-      <div class="game" onclick="location.href='#/game/nng';" style="cursor: pointer;">
+      <div class="game" onclick="location.href='#/g/hhu-adam/NNG4';" style="cursor: pointer;">
         <div class="wrapper">
           <div class="title">Natural Number Game</div>
           <div class="short-description">
diff --git a/client/src/components/LandingPage.tsx b/client/src/components/LandingPage.tsx
index 81b5ff6..7cdf947 100644
--- a/client/src/components/LandingPage.tsx
+++ b/client/src/components/LandingPage.tsx
@@ -47,8 +47,7 @@ function GameTile({
 
   let navigate = useNavigate();
   const routeChange = () =>{
-    let path = `game/${gameId}`;
-    navigate(path);
+    navigate(gameId);
   }
 
   return <div className="game" onClick={routeChange}>
@@ -108,7 +107,7 @@ function LandingPage() {
 
       <GameTile
         title="Formaloversum"
-        gameId="adam"
+        gameId="g/hhu-adam/Robo"
         intro="Erkunde das Leansche Universum mit deinem Robo, welcher dir bei der Verständigung mit den Formalosophen zur Seite steht."
         description="
 Dieses Spiel führt die Grundlagen zur Beweisführung in Lean ein und schneidet danach verschiedene Bereiche des Bachelorstudiums an.
@@ -120,7 +119,7 @@ Dieses Spiel führt die Grundlagen zur Beweisführung in Lean ein und schneidet
 
       <GameTile
         title="Natural Number Game"
-        gameId="nng"
+        gameId="g/hhu-adam/NNG4"
         intro="The classical introduction game for Lean."
         description="In this game you recreate the natural numbers $\mathbb{N}$ from the Peano axioms,
 learning the basics about theorem proving in Lean.
diff --git a/client/src/components/Level.tsx b/client/src/components/Level.tsx
index fab7bd9..7fae3d8 100644
--- a/client/src/components/Level.tsx
+++ b/client/src/components/Level.tsx
@@ -221,8 +221,8 @@ function PlayableLevel({worldId, levelId}) {
             </div>
           }
           {levelId >= gameInfo.data?.worldSize[worldId] ?
-          <Button to={`/game/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button> :
-          <Button to={`/game/${gameId}/world/${worldId}/level/${levelId + 1}`}>
+          <Button to={`/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button> :
+          <Button to={`/${gameId}/world/${worldId}/level/${levelId + 1}`}>
             Next&nbsp;<FontAwesomeIcon icon={faArrowRight} /></Button>}
 
         </div>}
@@ -257,8 +257,8 @@ function Introduction({worldId}) {
       </div>
       <div className="conclusion">
         {0 == gameInfo.data?.worldSize[worldId] ?
-        <Button to={`/game/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button> :
-        <Button to={`/game/${gameId}/world/${worldId}/level/1`}>
+        <Button to={`/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button> :
+        <Button to={`/${gameId}/world/${worldId}/level/1`}>
           Start&nbsp;<FontAwesomeIcon icon={faArrowRight} />
         </Button>}
       </div>
@@ -272,7 +272,7 @@ function LevelAppBar({isLoading, levelId, worldId, levelTitle}) {
 
   return <div className="app-bar" style={isLoading ? {display: "none"} : null} >
     <div>
-    <Button to={`/game/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button>
+    <Button to={`/${gameId}`}><FontAwesomeIcon icon={faHome} /></Button>
       <span className="app-bar-title">
         {gameInfo.data?.worlds.nodes[worldId].title && `World: ${gameInfo.data?.worlds.nodes[worldId].title}`}
       </span>
@@ -282,10 +282,10 @@ function LevelAppBar({isLoading, levelId, worldId, levelTitle}) {
         {levelTitle}
       </span>
       <Button disabled={levelId <= 0} inverted={true}
-        to={`/game/${gameId}/world/${worldId}/level/${levelId - 1}`}
+        to={`/${gameId}/world/${worldId}/level/${levelId - 1}`}
         ><FontAwesomeIcon icon={faArrowLeft} />&nbsp;Previous</Button>
       <Button disabled={levelId >= gameInfo.data?.worldSize[worldId]} inverted={true}
-        to={`/game/${gameId}/world/${worldId}/level/${levelId + 1}`}
+        to={`/${gameId}/world/${worldId}/level/${levelId + 1}`}
         >Next&nbsp;<FontAwesomeIcon icon={faArrowRight} /></Button>
     </div>
 
diff --git a/client/src/components/Welcome.tsx b/client/src/components/Welcome.tsx
index 0c66c5b..0382b6b 100644
--- a/client/src/components/Welcome.tsx
+++ b/client/src/components/Welcome.tsx
@@ -39,7 +39,7 @@ function LevelIcon({ worldId, levelId, position }) {
 
   // TODO: relative positioning?
   return (
-    <Link to={`/game/${gameId}/world/${worldId}/level/${levelId}`}>
+    <Link to={`/${gameId}/world/${worldId}/level/${levelId}`}>
       <circle fill={completed ? "green" :"#999"} cx={x} cy={y} r={r} />
     </Link>
   )
@@ -76,13 +76,13 @@ function Welcome() {
       for (let i = 1; i <= gameInfo.data.worldSize[id]; i++) {
         svgElements.push(
           <LevelIcon
-            key={`/game/${gameId}/world/${id}/level/${i}`}
+            key={`/${gameId}/world/${id}/level/${i}`}
             position={position} worldId={id} levelId={i} />
         )
       }
 
       svgElements.push(
-        <Link key={`world${id}`} to={`/game/${gameId}/world/${id}/level/0`}>
+        <Link key={`world${id}`} to={`/${gameId}/world/${id}/level/0`}>
           <circle className="world-circle" cx={s*position.x} cy={s*position.y} r={R}
               fill="#1976d2"/>
           <foreignObject className="world-title-wrapper" x={s*position.x} y={s*position.y}
diff --git a/client/src/index.tsx b/client/src/index.tsx
index 3232b70..a51bd57 100644
--- a/client/src/index.tsx
+++ b/client/src/index.tsx
@@ -22,19 +22,18 @@ const router = createHashRouter([
   {
     path: "/",
     element: <LandingPage />,
-    // loader: () => redirect("/game/adam")
   },
   {
-    path: "/game/:gameId",
+    path: "/g/:owner/:repo",
     element: <App />,
     errorElement: <ErrorPage />,
     children: [
       {
-        path: "/game/:gameId",
+        path: "/g/:owner/:repo",
         element: <Welcome />,
       },
       {
-        path: "/game/:gameId/world/:worldId/level/:levelId",
+        path: "/g/:owner/:repo/world/:worldId/level/:levelId",
         element: <Level />,
       },
     ],
diff --git a/package.json b/package.json
index 4f6fac5..a1c99c5 100644
--- a/package.json
+++ b/package.json
@@ -66,10 +66,10 @@
     "start": "concurrently -n server,client -c blue,green \"npm run start_server\" \"npm run start_client\"",
     "start_server": "cd server && lake build && NODE_ENV=development nodemon -e mjs --exec \"node ./index.mjs\"",
     "start_client": "NODE_ENV=development webpack-dev-server --hot",
-    "build": "npm run build_server && npm run build_client",
-    "build_server": "server/build.sh",
-    "build_client": "NODE_ENV=production webpack",
+    "build": "NODE_ENV=production webpack",
     "production": "NODE_ENV=production node server/index.mjs",
+    "build_robo": "rm -rf ./Robo && git clone https://github.com/hhu-adam/Robo && docker build ./Robo --file ./Robo/Dockerfile --tag github-hhu-adam:Robo && rm -rf ./Robo",
+    "build_nng": "rm -rf ./NNG4 && git clone https://github.com/hhu-adam/NNG4 && docker build ./NNG4 --file ./NNG4/Dockerfile --tag github-hhu-adam:NNG4 && rm -rf ./NNG4",
     "update_lean": "./UPDATE_LEAN.sh"
   },
   "eslintConfig": {
diff --git a/server/build.sh b/server/build.sh
deleted file mode 100755
index 7825db7..0000000
--- a/server/build.sh
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/usr/bin/env sh
-
-# Operate in the directory where this file is located
-cd $(dirname $0)
-
-# Build Adam
-( rm -rf adam
-  git clone https://github.com/hhu-adam/Robo adam/
-  cd adam
-  docker rmi adam:latest || true
-  docker build \
-    --rm -f Dockerfile -t adam:latest .
-)
-
-# Build NNG
-( rm -rf nng
-  git clone https://github.com/hhu-adam/NNG4 nng/
-  cd nng
-  docker rmi nng:latest || true
-  docker build \
-    --rm -f Dockerfile -t nng:latest .
-)
diff --git a/server/index.mjs b/server/index.mjs
index b63602e..22ce928 100644
--- a/server/index.mjs
+++ b/server/index.mjs
@@ -9,14 +9,20 @@ import os from 'os';
 import anonymize from 'ip-anonymize';
 import { importTrigger, importStatus } from './import.mjs'
 
+/** Preloaded games. The keys refer to the docker tags of the virtual machines.
+ * The number `queueLength` determines how many instances of the docker container
+ * get started before any user shows up to have them up and running immediately.
+ * The values `name`, `module`, and `dir` are just used for development where we
+ * use a project directory instead of a docker container.
+*/
 const games = {
-    adam: {
+    "github-hhu-adam:Robo": {
         name: "Adam",
         module: "Adam",
         dir: "../../../../Robo",
         queueLength: 5
     },
-    nng: {
+    "github-hhu-adam:NNG4": {
         name: "NNG",
         module: "NNG",
         dir: "../../../../NNG4",
@@ -50,17 +56,18 @@ const isDevelopment = environment === 'development'
 
 /** We keep queues of started Lean Server processes to be ready when a user arrives */
 const queue = {}
-const queueLength = 5
 
-function startServerProcess(gameId) {
-    const serverProcess = isDevelopment
-        ? cp.spawn("./gameserver",
-            ["--server", games[gameId].dir, games[gameId].module, games[gameId].name],
+function startServerProcess(tag) {
+    let serverProcess
+    if (isDevelopment && games[tag]?.dir) {
+        serverProcess = cp.spawn("./gameserver",
+            ["--server", games[tag].dir, games[tag].module, games[tag].name],
             { cwd: "./build/bin/" })
-        : cp.spawn("docker",
-            ["run", "--runtime=runsc", "--network=none", "--rm", "-i", `${gameId}:latest`,
-              "./gameserver", "--server", "/game/", games[gameId].module, games[gameId].name],
+    } else {
+        serverProcess =  cp.spawn("docker",
+            ["run", "--runtime=runsc", "--network=none", "--rm", "-i", `${tag}`],
             { cwd: "." })
+    }
     serverProcess.on('error', error =>
         console.error(`Launching Lean Server failed: ${error}`)
     );
@@ -73,32 +80,35 @@ function startServerProcess(gameId) {
 }
 
 /** start Lean Server processes to refill the queue */
-function fillQueue(gameId) {
-    while (queue[gameId].length < games[gameId].queueLength) {
-        const serverProcess = startServerProcess(gameId)
-        queue[gameId].push(serverProcess)
+function fillQueue(tag) {
+    while (queue[tag].length < games[tag].queueLength) {
+        const serverProcess = startServerProcess(tag)
+        queue[tag].push(serverProcess)
     }
 }
 
-for (let gameId in games) {
-    queue[gameId] = []
-    fillQueue(gameId)
+if (!isDevelopment) { // Don't use queue in development
+    for (let tag in games) {
+        queue[tag] = []
+        fillQueue(tag)
+    }
 }
 
-const urlRegEx = new RegExp("^/websocket/(.*)$")
+const urlRegEx = /^\/websocket\/g\/([\w.-]+)\/([\w.-]+)$/
 
 wss.addListener("connection", function(ws, req) {
     const reRes = urlRegEx.exec(req.url)
     if (!reRes) { console.error(`Connection refused because of invalid URL: ${req.url}`); return; }
-    const gameId = reRes[1]
-    if (!games[gameId]) { console.error(`Unknown game: ${gameId}`); return; }
+    const owner = reRes[1]
+    const repo = reRes[2]
+    const tag = `github-${owner}:${repo}`
 
     let ps;
-    if (isDevelopment) { // Don't use queue in development
-        ps = startServerProcess(gameId)
+    if (!queue[tag] || queue[tag].length == 0) {
+        ps = startServerProcess(tag)
     } else {
-        ps = queue[gameId].shift() // Pick the first Lean process; it's likely to be ready immediately
-        fillQueue(gameId)
+        ps = queue[tag].shift() // Pick the first Lean process; it's likely to be ready immediately
+        fillQueue(tag)
     }
 
     socketCounter += 1;