I started building minesweeper.org in 1999 while working on my Physics PhD. The goal was to teach myself web development. The result was a Java 1.1.5 applet that crashed browsers, required Netscape 4.0 or Internet Explorer 3.0, and reset its high scores every day at 0 Swatch internet time. My sister Becca helped me write the instructions. The site went live in 2000, and against all odds, people actually came to play.
But from the very first version, the site was about more than a puzzle game. Right there on the homepage was a photo of Princess Diana and a link to support her campaign to ban landmines. A banner across the top urged visitors to support the HALO Trust. That's why I called it Lady Di's Mines.
If you're curious, the Wayback Machine still has the original 2002 page. The old site had some security issues, so treat it as a museum piece — but it's all there: the Java applet, the daily scores, Diana's photo, and the HALO Trust banner.
Why Diana?
In January 1997, Diana walked through an active minefield in Huambo, Angola, wearing HALO Trust body armor. She met children who had lost their limbs. She spoke out, was criticized by politicians, and kept going. She visited mine-clearance operations in Bosnia just weeks before her death in August 1997. Her efforts helped build the momentum that led to the Ottawa Mine Ban Treaty, signed by 122 nations that December. Diana didn't live to see it.
Here was a game called "minesweeper" that millions of people played every day. If even a few of the people who came to my site paused to think about real mines, or clicked through to learn about the HALO Trust, it was worth doing.
The Return
Today, Lady Di's Mines is back — rebuilt from scratch with Python, FastAPI, and modern web technologies. It works on desktop and mobile, no plugins required, and there is a mode where every puzzle is logically solvable — no 50/50 guesses.
The game has grown far beyond Easy, Medium, and Hard. There's now Rush for speed chasers, real-time Duel and PvP multiplayer, Tentaizu for pure logic puzzles, Variants with alternative rulesets, daily Quests, and a global leaderboard that resets at midnight UTC. The site is available in ten languages. Every feature and every line of code is original work, built by me and the team at Regis Consulting with contributions from Earl Gero and William Murray.
Try the Diana Theme
Activate the dedicated Diana theme by adding ?theme=diana to any minesweeper.org URL — or use this direct link:
The theme wraps the classic minesweeper grid in a deep blue textured background with the Lady Di's Mines logo at the top. It's a nod to the original site's look and feel, updated for 2026. It works across all game modes, from Beginner to PvP.
The Cause Hasn't Gone Away
The HALO Trust has destroyed over 14 million explosives across more than 30 countries since its founding in 1988. The minefield Diana walked through in Huambo is now a neighborhood with homes and schools. But the conflict in Ukraine has brought a devastating resurgence of mine-laying, and dozens of countries remain contaminated. Diana's wish that all landmines be banned in her lifetime did not come true.
If you'd like to help, consider supporting The HALO Trust — the world's largest humanitarian mine clearance organization and the charity Diana worked with directly in Angola. You can also find links to other landmine organizations on the minesweeper.org about page.
Come Play
Twenty-five years after I first put Diana's photo on a minesweeper website, the connection still feels right. Come play at minesweeper.org. And if you have a moment, think about why the game is called what it's called.
Diana's wish didn't come true in her lifetime. You can help make it come true in yours.
Peace — Richard Cross