Free to play
There are many puzzles and questions that don't use AI that you can play for free. No limits, no gimmicks, no ads. You get 5 free AI evaluations every week for 3 months, with the option to buy credit packs or subscribe for more.
Choose your plan
Play for free, buy credits when you need them, or subscribe for a monthly allowance. Multiple-choice and short-answer puzzles never count against your quota.
Activity Credits
- 50 credits — $1.99
- 150 credits — $4.99
- 500 credits — $12.99
- 1 credit = 1 AI evaluation
- Never expire, roll over
- Buy as needed
Puzzler
- ★ Unlimited Puzzle Generation
- 250 AI evaluations / month
- Efficient AI scoring models
- Everything in Free
- 50% savings vs credit packs
Educator
- ★ Unlimited Puzzle Generation
- 500 AI evaluations / month
- Advanced AI Models
- Content Authoring Tools
- Multi-user Accounts
Riddlewords was created by the engineers and entrepreneurs at Fractionl. These apps are passion projects we work on to create things that are fun, helpful, intellectually stimulating, and that bring people together.
Our apps are free of ads, add-ons, and gimmicks. The subscriptions and ability to purchase AI credits are there to cover the costs of using AI services.
PricingFree vs AI Usage
Only the free-form answer type uses AI, and only those calls count against your monthly quota.
Free To Play
These puzzles have simple answers that do not require AI evaluation. You're free to play all of these puzzles as many times as you like. New puzzles are added every month.
- Multiple-choice questions
- Short-answer questions (scored locally)
- True/false questions
- Hints, explanations, fallacy reveals
- Browsing, rating, commenting, leaderboards
AI quotas
These questions have more complex logic, or are based off of knowledge frameworks with multi-axes scoring. Your answers are sent to an AI model for nuanced scoring. That's the cost we pass on.
- Free-form open-ended answers
- Multi-axis reasoning scoring
- Category-specific rubric evaluation
- Feedback on why your answer scored as it did
Content Creators
If you're interested in being a content creator, contact us. You'll get access to AI content generators, question review pipelines, and a growing set of authoring tools.
Contact us
Model choice
Educator users can switch between two evaluation tiers. Everyone else stays on our Efficient AI scoring models, which are fast, accurate, and handle the vast majority of scoring well.
Efficient AI scoring models default
Every tier's default. Handles the three standard axes (correctness, reasoning, specificity) very well on most puzzles.
- 1 credit per evaluation
- Fast — typically under 2 seconds
- Used on all plans by default
Advanced Scoring Models Educator only, opt-in
More nuanced evaluation on complex framework puzzles (systems thinking, fallacies, emergent reasoning). Use it when you want harder scoring or deeper feedback.
- 16 credits per evaluation
- Same Educator quota — 500 efficient calls or ~31 advanced calls, or any mix
- Toggle any time from your account page
Questions
What happens when I run out of credits?
Free-form questions that require AI evaluation become unavailable until you buy more credits, your weekly free allowance resets, or you subscribe. Every other puzzle type keeps working.
When do free evaluations reset?
Free users get 5 AI evaluations per week, resetting weekly for 3 months from first use. Subscription quotas reset on the first of each calendar month. Purchased credits never expire.
Can I change plans?
Any time. Upgrades take effect immediately with prorated billing. Downgrades apply at the end of your current billing period so you keep what you paid for.
Do credits roll over?
Purchased credits never expire and always roll over. Subscription quotas reset to the full allowance each month — unused subscription evaluations don't carry forward.
Why meter AI specifically?
Every other part of Riddlewords has near-zero cost per use. AI evaluation is the only thing that costs us per request — so it's the only thing we pass on. We'd rather keep everything else free forever than bundle it into a subscription.
What about refunds?
If you're unhappy with your plan within 14 days of upgrading, email us and we'll refund you. After that, cancellations stop future billing but don't refund the current period.
Start free, upgrade only if you need to
5 free AI evaluations a week is enough for most players. Create an account and find out.
Get started free