1v1 anything, anytime.

Duelo is a head-to-head brain-games app. It bundles ten games — word games, board games and puzzles — and lets you play any of them against one specific friend. All ten work live; seven of them — the five word games, Sudoku and Queens — also work asynchronously, so neither of you has to be online at the same time. Every result feeds a permanent record against that person.

Yes. Anytime mode lets you send a challenge your opponent plays whenever they like; the app compares your results and updates your head-to-head record. This is the mode most people end up living in, because live play needs two people free at the same moment.

Yes, free to play, and there is no subscription. A one-off Pro purchase removes ads and unlocks cosmetics. It grants no competitive advantage of any kind — it cannot buy you a win.

A person you chose, every time. You invite a friend, or send a challenge link to anyone. There is no matchmaking, no queue and no stranger pool. There are no bots either — nothing on a leaderboard that isn't someone. If they're not online, you leave a challenge instead of playing a machine.

Crossword Chaos (Real-time clue duels), Word Chaser (Hidden-word hunt), Cluster Clash (Group the words), Cipher Storm (Five-letter word race), Path Pursuit (Trace-and-claim word grid), Four in a Row (Drop & line up four), Sudoku (Solve it together), Bomb Pass (Hot potato, but explosive), Trapdoor Panic (Cross the hidden minefield), Queens (One per row, column & color).

Live means both players are online at once — either racing the same board simultaneously, or alternating turns on a shared one. Async means one player sends a challenge and the other answers it later. Async is what keeps a rivalry alive across time zones and busy weeks.

Yes — Duelo has co-op Sudoku, where two players fill in the same board live rather than racing separate copies of it. There are no turns; either player can fill any empty cell at any time.

Competitive duels are rated with Glicko-2, the system used in competitive chess. Unlike plain Elo it also tracks how confident it is in your rating, so a new player's number settles quickly. Co-op games are unrated, because a shared solve has no losing side.

You need one to keep a head-to-head record against a specific friend, since the record has to belong to someone. Joining a live room a friend has shared works from a link.