Mindreader: a 2-player word game where the prompter wins by getting their opponent to guess exactly 30% right (or 70%, or 10%…)
Hey r/puzzlegames,
I've been building a small browser game called Guess Prompt for the past year and a half, and I just shipped a new mode I'm really proud of called Mindreader. Looking for a handful of puzzle people to play it and tell me where the design breaks.
The twist: It's a 2-player word game built around AI image generation, but the puzzle isn't "guess the picture." It's about calibration.
Every turn, one player is the Prompter and the other is the Guesser:
- The Prompter writes a prompt, an AI generates an image, and the Prompter is given a random target similarity (anywhere from 0% to 100%, in 10% buckets).
- The Guesser sees the image and tries to describe it as accurately as possible.
- We measure the cosine similarity between the two texts.
- Prompter scores: 100 − |target − actual| (reward for nailing the target)
- Guesser scores: actual % (reward for nailing the image)
So if the target is 30% and the Guesser scores 28%, the Prompter gets 98 points — but the Guesser only gets 28. Asymmetric scoring means you can't just "play normal" — the Prompter has to design a prompt that pulls the Guesser's natural description toward a specific accuracy. Crafting a prompt that elicits exactly 70% similarity is way harder than it sounds.
If either player lands within 2% of the target, it's a Mindread — instant win. First to 1000 points otherwise.
Strategy that emerged in playtesting:
- High target (90%+): write the most concrete, unambiguous prompt you can ("a red apple on a wooden table")
- Low target (0–20%): write something abstract or with a hidden twist the image can't fully capture
- Mid targets (40–60%): easiest — you need a prompt that's partly describable but has elements that pull the description off-track
There's a image-prompt fidelity penalty so you can't game it by writing "a tricky image impossible to describe" and getting a wildly unrelated image — your score gets dampened if the image doesn't match your own prompt.
You can play:
- Against an AI opponent
- Against another human (sign-in via Google, separate Elo leaderboard)
Free, no ads in your face, no app install. Just a browser link: https://guessprompt.com
I'd love feedback on:
Does the asymmetric scoring feel fair, or is it bad that it can lopsidedly favor the Prompter?
Are the target buckets too punishing at the extremes (0% and 100%)?
Anything that confuses you in the first 30 seconds — UX needs polishing
Happy to answer any design questions in the comments. Thanks for taking a look.