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Friendly cartoon kids playing grid strategy games — Connect 4, Gomoku stones, a hex board and Reversi — in a bright sunlit games room

GridForge

Four ideas. Five games. One grid. Learn the moves that win Connect 4, Gomoku, Hex, Reversi, and Dots & Boxes — the double threat, the connection, flipping territory, and parity.

Play Connect 4 Learn to win
Level 1

Start here

Connect 4 Drop pieces to make four in a row — build a double threat the opponent cannot block both ways. Gomoku Five in a row on the open grid — make two threats at once and the game is won. Hex Connect your two sides across the board — one unbroken chain, and there is always a winner. Reversi Flip the line between your pieces — hold the corners and control the whole board.
Brain Break Take a quiet moment between games — a fun riddle or a short breather. Brain breaks help you remember what you learn.

All activities

Play a game

Connect 4 Drop pieces to make four in a row — build a double threat the opponent cannot block both ways. Gomoku Five in a row on the open grid — make two threats at once and the game is won. Hex Connect your two sides across the board with one unbroken chain — there is always exactly one winner. Reversi Flip the line of pieces between yours — hold the corners and control the whole board. Dots & Boxes Draw a line, close a box, take another turn — count the chains and sacrifice to win. Connect 4 — Pop Out Connect-4 with a twist: drop a disc OR pop one of your own out of the bottom, sliding the whole column down. A pop can make four for both of you — and whoever moved wins. Renju Gomoku made fair. You play Black under the professional forbidden-move rule — no double-three, double-four, or six-in-a-row — and win with exactly five. Play a Friend Share a room code and play a friend on the same board — a quick networked match. Pass-and-Play Two players share one device and take turns — the same real games, face to face. Little Grid (ages 6–8) A gentle, audio-first first taste of Connect 4 for younger players — dropping a coin, how it always falls to the bottom, and lining up four in a row. Big buttons, read aloud.

Sharpen your play

Learn to Win Four ideas that win across all five games — connection, the double threat, flipping territory, and parity. Board Vision Train your eye for the grid — where a line can extend, and where a threat is one move away. Pattern Trainer Learn the recurring shapes — the forks and double-threats that come up again and again. Tactics Find the winning move — read the position and pick the line that forces the win. Predict the Move Call the best move — or the winning threat — BEFORE the reveal, then find out why. A guess is the point.

Practice & together

Mixed Practice A short round across the kits you have played — brought back to make it stick. Tactics Rush A calm minute on tactics you already know — the clock counts up, stop whenever you like, no penalty for a miss. Trick Questions Brain-teasers with a twist — spot why the obvious move is a trap. Teach the Cast Teach a winning idea to a cast member still learning it — teaching makes it stick. Grid Duel (hotseat) 2–4 players take turns on one device — same questions for everyone, highest first-try score wins. Grid Quest — the map A progression trail through every kit. Clear each stop of real practice, then move on. Progress Your levels, days active, and how each skill area is coming along — saved on this device. My Games Every game you play is saved on this device — replay it move by move and get a kind, move-by-move review of your Connect-4 games. Nothing that names you leaves the device.
Concept Kits — 16 kits of connection-game strategy

A short round of questions with a hint whenever you get stuck. Progress stays on this device.

Kit 1: Connect-4 Basics Connection · grades 4-5 · 25 questions Kit 2: The Fork Double-Threats · grades 4-5 · 25 questions Kit 3: Blocking & Threats Double-Threats · grades 4-5 · 25 questions Kit 4: Solved Games Connection · grades 5-6 · 25 questions Kit 5: Gomoku Connection · grades 5-6 · 25 questions Kit 6: Open Threes & Fours Double-Threats · grades 5-6 · 25 questions Kit 7: Hex — Connection Paths Connection · grades 6-7 · 25 questions Kit 8: Hex Strategy Connection · grades 6-7 · 25 questions Kit 9: Reversi Basics Territory / Flip · grades 6-7 · 25 questions Kit 10: Corners & Stability Territory / Flip · grades 6-7 · 25 questions Kit 11: Mobility & Territory Territory / Flip · grades 7-8 · 25 questions Kit 12: Dots-&-Boxes Basics Parity · grades 6-7 · 25 questions Kit 13: Parity & The Chain Rule Parity · grades 7-8 · 25 questions Kit 14: The Double-Cross Parity · grades 7-8 · 25 questions Kit 15: Spot the Shared Primitive Transfer · grades 7-8 · 25 questions Kit 16: Capstone — Grid Games Synthesis Transfer · grades 7-8 · 25 questions

More ways to play

Quiz Arena Grid Run Quiz Duel Best Moves Skills
Where this game comes from

Reversi

Reversi was invented in London in the 1880s. Two Englishmen, Lewis Waterman and John Mollett, each claimed they had invented it first.

One thing to hold: Each disc is dark on one side and light on the other, so it can change sides.

Why it matters: Nothing is ever safe until the end: one move can flip a whole line.

Sources: H. J. R. Murray, A History of Board-Games other than Chess (1952)

Hex

Hex was invented twice. Piet Hein, a Danish poet, invented it in 1942. John Nash, a young American mathematician, invented it again in 1948.

One thing to hold: The board is a diamond of hexagons, and the game has no draws.

Why it matters: Nash proved the first player can always win if they play perfectly, but nobody knows the winning moves on a big board.

Sources: Martin Gardner, “The Game of Hex”, Scientific American (1957) · Ryan B. Hayward and Bjarne Toft, Hex: The Full Story (2019)

Dots and boxes

Dots and boxes was first written down by Édouard Lucas, a French mathematician, in 1889. He called it la pipopipette.

One thing to hold: All you need is a pencil and a page of dots.

Why it matters: It looks like luck, but it is a game of counting: near the end, the player who can count the long chains can choose who gets them.

What we don’t know: Children may well have played it before Lucas wrote it down; nobody knows.

Sources: Elwyn Berlekamp, The Dots and Boxes Game (2000)

Gomoku

Gomoku, “five in a row”, is played in Japan on a Go board with Go stones. Its tournament form was given the name renju in 1899; the extra rules that slow Black down were added over the years after.

One thing to hold: The same board and the same stones as Go, used for a different game.

Why it matters: Black, who moves first, has a big advantage, so players kept adding rules to make the game fair. Fairness is part of the design.

What we don’t know: How old five-in-a-row games are, and where they began, is not known.

Sources: R. C. Bell, Board and Table Games from Many Civilizations (1960; rev. 1979) · Renju International Federation, “History of renju”

GridForge mascot

Meet the cast — the characters who teach this

Each one stands for an idea you’ll practice. Tap a character to read their illustrated story and hear their audio drama.

Ensemble stories — the cast together

Explore all the stories →

What next? Pick a door

Chosen from what this app is about. What you open is remembered on this device only.

📚 Books for GridForge

Read the story, print a workbook, or color the cast — free PDFs to read offline or print at home.

Browse all books →

Built from these ludemes

A ludeme is a building block of a game's rules. This one combines:

Connection Flip (custodial capture) Capture

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