Global Game Jam: How It Works and How to Finish a Game

The Global Game Jam is a yearly event where thousands of people, spread across hundreds of local sites around the world, each build a game from scratch in about 48 hours around one theme that nobody knows in advance. If you have never jammed before, it is one of the friendliest places to start: teams form on the spot, beginners are welcome and the goal is a finished, playable game rather than a polished product. This guide explains how the event works, what the numbers and past themes look like, and how to plan your weekend so you actually submit something.

What is the Global Game Jam?

A game jam is an event where participants make a game, usually a video game, from nothing in a short, fixed amount of time. The Global Game Jam (GGJ) is the biggest of these held in physical locations. It is run by Global Game Jam, Inc., a US non-profit charity based in San Luis Obispo, California, and it relies on more than a thousand volunteers to run the local sites.

The idea came from the Nordic Game Jam. Susan Gold, Ian Schreiber, Gorm Lai and Foaad Khosmood created the Global Game Jam under the International Game Developers Association’s education group, and the first edition ran from January 30 to February 1, 2009, at 53 locations, where 1,650 participants made 370 games, according to its Wikipedia entry. By 2012 it was recognised by Guinness World Records as the largest game jam in the world.

The “global” part means distributed. There is no single venue. Universities, studios, libraries and community groups each host a site, and every site works from the same theme at roughly the same time. Some sites are online. Participants range from professional developers to students, teachers, artists and people who have never made a game, and board games are as valid as digital ones.

How the Global Game Jam works: theme, 48 hours and diversifiers

The classic format runs for 48 hours in each time zone, starting at 5 PM on the first day and ending at 5 PM two days later. The recommended schedule looks like this, though sites are free to adapt it:

1. Theme reveal. Everyone receives the same theme at the start. Past themes include “Extinction” (2011), “Repair” (2020), “Bubble” (2025) and “Mask” (2026).
2. Brainstorm and pitch. People share rough ideas and pitch them to the room.
3. Team forming. Small teams gather around the pitches they like. You do not need to arrive with a team.
4. Build. Development runs until about 3 PM on the final day.
5. Present. The last couple of hours are for showing games to each other and uploading them to the jam site.

Alongside the theme, you get a list of optional “diversifiers”, sometimes called achievements. These are extra constraints, such as a specific control scheme or accessibility goal, designed to push your design somewhere unexpected. They are not required, but they are a good tiebreaker when your team is stuck between two ideas.

Recent editions have published a week-long window (2025 ran January 20 to 26) and 2022 stretched to ten days, so check your local site’s page for its actual hours. The 48-hour sprint is still the core experience at most in-person sites.

Who owns what you make?

Games submitted to the Global Game Jam are released under the Creative Commons Non-Commercial Share-Alike 3.0 licence. The intellectual property stays with the creators, the GGJ may use any game for promotion, and every entry is archived on the jam’s website, often with source code. If your team wants to turn the prototype into a commercial game later, agree on ownership before the jam ends.

Global Game Jam themes and numbers by year

The event grew quickly, dipped during the online-only 2021 edition and has since passed its old records. These figures come from the GGJ’s Wikipedia history.

Year	Theme	Locations	Games made
2009	“As long as we have each other, we will never run out of problems”	53	370
2012	An image of an Ouroboros	242	2,209
2019	“What home means to you”	860	9,010
2020	“Repair”	934	9,601
2021	“Lost and Found” (online only)	585	6,383
2024	“Make Me Laugh”	796	9,964
2025	“Bubble”	795	12,098
2026	“Mask”	Theme announced; see the GGJ archive for results

Two patterns are worth noticing. Themes are deliberately loose, often a phrase, an image or even a sound (2013’s theme was the sound of a heartbeat), so any genre can fit. And the number of games per site keeps rising: 2025 produced more games than 2020 from fewer locations, which suggests teams are getting smaller and tools are getting faster.

Is the Global Game Jam the biggest game jam?

For in-person events, yes. In 2025 the Global Game Jam had 35,371 registered participants at 795 sites in 97 countries, and in 2024 it reached all seven continents for the first time. No other jam runs a comparable network of physical sites.

Other jams are huge in a different way. Ludum Dare and the GMTK Game Jam are mostly online, solo-friendly events where you work from home and submit through a website. Here is how the formats compare in practice:

	Global Game Jam	Online jams (Ludum Dare, GMTK and similar)
Where	Local sites, some online	At home
Teams	Usually formed on the spot	Often solo or pre-arranged
Feedback	Live presentations to the room	Ratings and comments online
Best for	Meeting people, first team project	Practising solo, flexible schedule

If your goal is to meet other developers or find future collaborators, the Global Game Jam is hard to beat. If you prefer working alone at your own desk, an online jam fits better. Plenty of indie games started life as jam prototypes, so either route can lead somewhere.

How to prepare for the Global Game Jam

You cannot plan the game, because the theme is secret. You can plan everything around it.

Before the weekend

• Register at a site early. Popular sites fill up. Read its schedule, whether it stays open overnight and whether you need to bring your own machine.
• Set up your tools at home. Install and test your engine, version control and any asset tools. Make a throwaway “hello world” build and export it once, so you know the export step works.
• Pick a role. Programmer, artist, designer, audio, writer or producer. Beginners make excellent playtesters and producers; someone has to keep the scope honest.
• Know the rules on pre-made content. Read your site’s rules about pre-made assets, templates and AI-generated content before you rely on any of them, and credit what you use.

During the brainstorm

Write the theme in the middle of a sheet and list ten literal meanings, then ten sideways ones. For “Mask”, literal ideas are disguises and masquerade balls; sideways ideas are noise masking a sound, a gas mask in a polluted world, or a mask that hides part of the screen. The sideways ideas usually make better jam games because fewer teams pick them.

Then apply one test: can you describe the core action in a single verb? “Swap masks to change your abilities” passes. “An open-world mystery about identity” does not, at least not in 48 hours.

Using Sorceress to build a game jam entry fast

Most jam teams lose time in two places: getting a playable prototype running, and producing art and sound that match. Sorceress is a browser-based game creation suite built for exactly that kind of speed, so it fits the Global Game Jam weekend well, as long as your site allows AI-assisted tools.

WizardGenie for the prototype

WizardGenie is Sorceress’s AI game engine. You describe the game you want and it writes, runs and iterates on the code with you, which is the practical side of vibe coding: steering a program in plain language instead of typing every line. At a jam, that means a team without a strong programmer can still get a moving, testable prototype in the first evening.

It runs on the web with nothing to install, and as a Windows desktop app with an auto-updater that gives native file access and longer agent sessions, which helps when your site’s Wi-Fi is shaky or you want the project files on your own drive. WizardGenie works with the leading AI coding models, and you can switch models with your own API key. When the jam ends, export the build and host it wherever your site asks you to upload.

Art and audio that match

• Auto-Sprite v2 (Pro) creates game-ready 2D sprites, including characters, items and effects, in any art style, in three steps starting with generating a character. One artist can keep a whole cast visually consistent.
• Tileset Forge (Pro) turns AI art into game-ready tilesets, with background removal and seamless tiling in its Tile Studio. A tileset is a grid of small images that snap together to build levels.
• Sound Studio generates music, sound effects and text-to-speech voices, and includes an editor for trimming. Jam games with sound feel twice as finished in the presentation room.

If a teammate prefers another coding agent, the Sorceress API gives that agent one key to generate sprites, 3D models, music and sound effects too. For a map of every tool, see the Sorceress tools guide.

A 48-hour Global Game Jam plan, with a worked example

Say the theme is “Mask” and your team of three picks “swap masks to change your abilities”. Here is a schedule that leaves slack for the things that always go wrong.

Time	Goal
Friday 5–8 PM	Theme, brainstorm, pitch, form team, agree on one verb
Friday 8 PM–midnight	Grey-box prototype: shapes on screen, controls working
Saturday morning	Playtest the core loop; cut anything that is not fun
Saturday afternoon	Real art, first level, basic sound
Saturday evening	Second and third level, title and end screens
Sunday until noon	Bug fixes and polish only. Feature freeze.
Sunday noon–3 PM	Export, upload, write the description, take screenshots

The grey-box prototype is the most important step. Coloured rectangles are enough to tell whether swapping masks feels good. Below is a complete Phaser 3 example of that first hour: two “masks” with different speeds, swapped with the space bar. You can paste it into a page that loads Phaser, or ask WizardGenie for the same behaviour in plain English.

const masks = [
  { name: "FOX", color: 0xff8a3d, speed: 260 },
  { name: "OWL", color: 0x7ec8ff, speed: 140 }
];

let player, keys, label;
let current = 0;

function create() {
  player = this.add.rectangle(320, 180, 32, 32, masks[0].color);
  keys = this.input.keyboard.createCursorKeys();
  label = this.add.text(12, 12, "Mask: FOX (SPACE to swap)", { color: "#ffffff" });

  this.input.keyboard.on("keydown-SPACE", () => {
    current = (current + 1) % masks.length;
    player.setFillStyle(masks[current].color);
    label.setText("Mask: " + masks[current].name + " (SPACE to swap)");
  });
}

function update(time, delta) {
  const step = masks[current].speed * (delta / 1000);
  if (keys.left.isDown) player.x -= step;
  if (keys.right.isDown) player.x += step;
  if (keys.up.isDown) player.y -= step;
  if (keys.down.isDown) player.y += step;
}

new Phaser.Game({
  type: Phaser.AUTO,
  width: 640,
  height: 360,
  backgroundColor: "#1d1b2f",
  scene: { create, update }
});

Once this feels right, add the twist: maybe the fox is fast but cannot see in the dark, and the owl is slow but reveals hidden platforms. Only then generate the real fox and owl sprites and drop them in place of the rectangles. Art made before the mechanic is proven often gets thrown away.

Common game jam mistakes (and how to avoid them)

• Scoping for a month. If your idea needs more than one level type, one enemy type and one mechanic, cut it in half. Then cut it again.
• Polishing before it is playable. A beautiful menu on a broken game scores lower than ugly boxes that are fun.
• Leaving export to the last hour. Builds fail, uploads are slow and site Wi-Fi gets crowded at the deadline. Do a test export on Saturday.
• No instructions in the game. Judges and players spend under a minute deciding if they understand your game. Put the controls on the title screen.
• Skipping sleep. Tired teams introduce bugs faster than they fix them. Sleep at least one full night.
• Ignoring the theme in the pitch. If the connection to the theme is subtle, explain it in one sentence during your presentation and in the game description.
• Forgetting credits. List everyone on the team and every tool or asset source you used.

If you enjoy themed constraints, our guide to the death jam game idea shows another way to turn a tight prompt into a small, finishable design.

The jam weekend at a glance

The Global Game Jam is the world’s largest in-person game jam: one shared theme, hundreds of local sites, and roughly 48 hours to make a game with people you may have just met. Register at a site early, set up and test your tools before the weekend, pick one verb that captures the theme, and build a grey-box prototype on the first night. Spend Saturday on art, sound and levels, freeze features on Sunday morning, and export well before the deadline.

Tools that shorten the slow parts make a real difference in that window. A plain-language prototype in WizardGenie, consistent sprites from Auto-Sprite v2 and quick music and effects from Sound Studio let a small team spend more of the weekend on what judges and players remember: a game that is fun to play for two minutes and clearly about the theme. Your first Global Game Jam does not need to win anything. It needs to end with a game you finished, and a few new people you would happily jam with again.