Game guides
Short articles with a single job each. They link back to the games they describe.
Tic Tac Toe
How to Play Tic Tac Toe
Learn Tic Tac Toe in two minutes: setup, turns, how a line wins, and what to do when the board fills with no winner.
Tic Tac Toe Rules
The complete, short rule set for Tic Tac Toe: legal moves, winning lines, draws, and what does not count.
Tic Tac Toe Strategy
Practical Tic Tac Toe strategy: center vs corners, forced blocks, and how forks win games against imperfect opponents.
How to Never Lose at Tic Tac Toe
A perfect-play recipe for Tic Tac Toe. Follow it and you cannot lose. You can still be held to a draw.
Best First Move in Tic Tac Toe
Corner or center? Why both are drawing moves against perfect play, and which one wins more against people.
Is Tic Tac Toe a Game of Skill?
Tic Tac Toe is a solved game. Skill still shows up — in attention, not in hidden tactics.
How Tic Tac Toe AI Works
A plain-language explanation of minimax on a 3×3 board — the algorithm behind Duetly's unbeatable Hard mode.
Tic Tac Toe Online With Friends
How private invite links work on Duetly: create a room, share a code, play in real time, rematch without a new account.
Tic Tac Toe vs Computer
How Easy and Hard computer opponents differ, and how to use each one to practice without wasting a friend's time.
Can You Beat Perfect Tic Tac Toe AI?
No. A correct minimax opponent cannot lose. Here is what a draw looks like, and what a 'win' would actually mean.
Tic Tac Toe Unblocked: Play in Any Browser, Even Offline
Play Tic Tac Toe unblocked on a school Chromebook or work laptop. No download, no account, a local 2 player mode that works after the page loads, and an unbeatable computer.
Rock Paper Scissors
How to Play Rock Paper Scissors
The throw, the timing, and how a round is decided — plus how online play hides your choice until both people lock in.
Rock Paper Scissors Rules
Standard RPS rules: legal throws, the cycle of beats, draws, and how match formats count wins.
Rock Paper Scissors Strategy
Casual RPS is not Nash equilibrium. It is pattern spotting: what people throw after a loss, and how not to be readable.
Rock Paper Scissors Online With Friends
How to run a fair online RPS match: hidden choices, server-side results, and invite links that work on a phone.
Is Rock Paper Scissors Actually Random?
The rules are symmetric. Human throws are not. Where randomness really lives in RPS.
Best First Move in Rock Paper Scissors
There is no winning first throw against a random opponent. Against people, rock is common — which makes paper a popular counter.
Rock Paper Scissors Psychology
What people tend to do after they win, lose, or draw — and how to use that without turning the game into a lecture.
Best of 3 vs Best of 5
Why extra rounds reduce luck, how draws stretch a match, and which format to pick for a quick decision vs a real contest.
Rock Paper Scissors vs Computer
Duetly's computer opponent throws uniformly at random. You cannot out-think it. You can still use it to test formats.
How to Win More at Rock Paper Scissors
A short, honest list: hide your tells, do not repeat on autopilot, and pick a long enough match that luck is not the whole story.
UNO
How to Play UNO
Learn UNO in a few minutes: the 108-card deck, matching color or symbol, special cards, saying UNO, and how a round ends.
UNO Rules
The standard UNO rule set used on Duetly: legal plays, special cards, Wild Draw Four restriction, UNO callouts, and what the server rejects.
UNO Unblocked: Play at School or Work in Any Browser
Play UNO unblocked with no download and no account. Why browser UNO works on school Chromebooks and work laptops, what can still be blocked, and how to play vs bots or friends.
UNO Show No Mercy
How to Play UNO Show No Mercy
Learn UNO Show No Mercy (UNO No Mercy): 168 cards, stacking Draw +2/+4/+6/+10, 7 swaps, 0 passes, Skip Everyone, and the Mercy rule at 25 cards.
UNO Show No Mercy Rules (UNO No Mercy)
The official UNO No Mercy rule set as played on Duetly: stacking, Mercy at 25 cards, 7/0 hand rules, Skip Everyone, and Wild Draw 6/10. What the server accepts.
UNO Show No Mercy Cards Explained
Every card in the UNO No Mercy deck with counts and effects: Discard All, Skip Everyone, Draw 4, Wild Reverse Draw 4, Wild Draw 6, Wild Draw 10, and Color Roulette.
UNO Show No Mercy Strategy
Practical UNO No Mercy tips: when to hold draw cards for a stack, how to use 7 swaps and 0 passes, Mercy-rule math, and why Discard All wins more games than Draw 10.