4 vs Duel Stack

Go for 1st place or just avoid last — your strategy is your own. ■ Rules ① The basic rules are just like traditional Othello: players take turns placing stones and flip the opponent’s stones when sandwiching them. ② When the board is full, rankings from 1st to 4th are determined by who has the most stones. ③ If you can't make a valid move, you can place a stone on any empty space adjacent to an opponent’s piece. ■ Online Play ・Battle real-time with players around the world! ・Share a room code to easily play with friends. ・If fewer than four players join, CPU players will automatically fill in. Fully free to play — no hidden fees!

Stack blocks. Challenge players. Climb the ranks. Duel Stack is a fast-paced 1v1 block stacking game. Two players stack blocks at the same time on a split screen — land your blocks precisely or watch them shrink. Miss completely and you lose. DUEL MODE Play against real players online through Game Center. Every match affects your Elo rating. Can you reach the top of the leaderboard? POWER-UPS Choose your loadout from Freeze, Shield, Speed Boost, and Expand. Use coins to buy power-ups or watch ads for free ones — up to 3 per day. Bring 3 into each match and use them at the perfect moment. GAME MODES • Find Match — Ranked 1v1 duels online • Vs AI — Practice against bots • Solo — Stack as high as you can • Speed — Blocks get faster every drop • Challenge Friend — Invite Game Center friends DAILY REWARDS • Login bonus every day • First win of the day bonus • Win streak bonuses • Free power-up every 10 matches CUSTOMIZE Choose from 12 block skins, 8 color themes, 7 arena backgrounds, emoji packs, and particle effects. 5 themes and 4 arenas are free — no purchase needed. COMPETE • Elo ranking system • Global leaderboard • Daily challenges • 20+ achievements Free to play.