Six teams stand on the same corner by the Hôtel de Ville, all staring at their phones, all waiting for a blue dot to admit they've arrived. The dot is bouncing between two streets. Behind them a police cordon has just closed the quai they were about to walk down. The fireworks are in forty minutes.
That's a chasse au trésor on 14 July when it's been designed for a quiet Sunday. Bastille Day 2026 is a Tuesday, the centre of every French city will be full, and GPS gives up the moment the crowd arrives. Call it a treasure hunt in London or a Schnitzeljagd in Cologne and the same three things decide it: people need to join on the phones they already have, more than one language will be in the group, and everyone must not land on the same corner at once.
The version that works looks like this. You spend an evening in a web editor writing a few chapters, each with a handful of tasks: a photo to take, a code to type, a question to answer. On the 14th, players scan a QR code, a web page opens in their browser, they type a team name, and they're off. Nothing gets installed, which matters on a mairie's locked work phones. One person watches a dashboard, messages every team when a street closes, and ends the game when the restaurant calls. Up to 25 phones at once is free, with a small watermark; paid plans raise that number and change nothing else. That's PlayTours. Pricing and GDPR and ISO 27001 details have their own posts, and for a public fête, read the pricing one before buying a plan for everyone who might walk past.
Write it once, let people read it in their language
A company with offices in Lyon and Dublin doesn't need to build the hunt twice. In the editor you set the language you're writing in and switch on translation for players. Someone who opens the game in a different language taps once and reads your tasks in theirs.
Riddles are the exception. Machine translation will mangle wordplay, so write each riddle in one language and leave it there. Practical lines like "meet at the statue, fireworks at 23:00" translate fine. There's a longer multi-language guide if you want it.
Codes on plaques, not GPS on a crowded street
In a street that's shoulder to shoulder, asking the phone whether it's within 20 metres of a pin is a coin toss. Don't do it. Print a short code and tape it at waist height on a partner café or a town hall noticeboard. Players type it to unlock the task. Photo tasks work the same way: "a public tricolore that isn't a souvenir stall," checked automatically when the picture comes in.
Then spread the crowd. Pin the first chapter (safety and meeting point) and the last chapter (where to watch the display). Let the chapters in between shuffle, so every team walks a different route, and turn on crowd prevention, so when a team finishes a chapter PlayTours sends them to whichever chapter currently has the fewest people in it. Write any out-of-bounds areas into the chapter-one briefing so nobody gets sent across a cordon.
The Tuesday-evening office version
A lot of the mail we get from Europe is smaller than a civic fête: "the office is open, we have 40 people, we want 75 minutes before dinner."
For that, let teams do the tasks in any order, put six of them in the streets around the office, and set a time limit. The countdown can't be paused, so if the restaurant moves your booking, end the game from the dashboard. Give players a short link on the pyts.link domain rather than a URL that shouts a software brand at your guests; PlayTours provides one with every game.
The same skeleton works elsewhere. Switzerland on 1 August has hills, several languages, and early dark in some cantons, so shorten the photo list. Germany on 3 October has its own Schnitzeljagd outline. The UK summer bank holiday on 31 August has a different mood and the same crowd problem.
If your prefecture has a rule we should know about, email me at hello@playtours.app. A map helps more than a long brief.
-Mo
If you're building this in PlayTours
Editor names for the above: Instant Join for the QR and pyts.link address; Default language and Allow translation; Shuffle chapters with first and last kept fixed; Prevent bunching; access codes on tasks; AI-judged photo tasks; a session time limit; and the facilitator dashboard for messages and stopping the game. QuickBuild will draft four to eight tasks from a prompt in French or English; open the full editor after that to add the shuffle and a time lock on anything that collides with the fireworks.