Duel SIM: Strategy Board Game
Lines, dots, and no triangles.
Free · Designed for iPad. Not verified for macOS.
Two players. One device. Draw lines — don't complete a triangle or you lose. Train with AI first, then face someone for real. Built on Ramsey Theory.
Duel SIM is part of the Duel series — games built around one idea: your phone as a board game. Two people, same room, one device between them. No online mode, no matchmaking, no notifications. Just the game and whoever's sitting across from you.
Not ready to face a real opponent yet? Two built-in AI modes let you train first — and show up prepared.
Duel SIM is a two-player abstract strategy game rooted in Ramsey Theory — the mathematical field that proves some patterns are unavoidable.
OBJECTIVE
Players alternate drawing coloured lines between dots on a circular board. The player who completes a triangle in their own colour loses. Simple rule. Deep strategy.
GUARANTEED WINNER
By Ramsey theory, on a board of 6 or more dots a single-colour triangle MUST eventually appear. The game always ends — stalemates are mathematically impossible.
GAME MODES
• Local Duel — two players, one device, face to face
• vs AI Trainer — hone your strategy against a heuristic opponent
• vs AI Master — challenge the minimax engine for a serious fight
SETTINGS & DEPTH
• Board size: 6, 7, 8 or 9 vertices — more dots means longer, more complex games
• Partial Start — skip the quiet opening; jump straight into the tense endgame
• Helper Lines — toggle available-move hints on or off
• Match format — first player to reach a target score wins the match
• Custom player names
CLEAN & FOCUSED
No ads. No accounts. No internet required. Pick it up and play.
HOW TO PLAY
Tap any dot, then tap another to draw a line in your colour. Avoid being the player who closes a triangle. Force your opponent into doing it instead.
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A modern take on the classic pen-and-paper game of SIM, reimagined with neon visuals and a smooth touch interface. Part of the Duel series — turning phones back into board games.
The developer, Arkadiusz Szafraniec, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Arkadiusz Szafraniec
- Size
- 33.2 MB
- Category
- Board
- Compatibility
Requires iOS 13.0 or later.
- iPhone
Requires iOS 13.0 or later. - iPad
Requires iPadOS 13.0 or later. - iPod touch
Requires iOS 13.0 or later. - Mac
Requires macOS 11.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Arkudias