Share one screen
Choose local play, set the board and shapes, then start. Blue and Red share the same phone, tablet, or computer. In alternating turns, hand over control after each placement.
One board. Two rivals. No long setup.
Friendly rivalry.
Serious territory.
Settle it in thirty seconds. Share a phone, pass a tablet, or face a friend from another browser. Grow your shapes and leave them less room to win.
Free to playLocal + onlineNo download
YOUR TERRITORY0.0%
Try a movePick an opening. Your blue shape grows until it meets an edge or a rival.
Real game geometry. Three openings. Which claims more?
One devicePass-and-play, side by sideTwo browsersA private room for your friendOne winnerWhoever claims more space
Two-player game
Same sofa?
Different cities? Your call.
Choose by how you want to connect. Both routes use the same growing-shape rules.
Open a private room
Open Rooms, choose Create room, and select your match rules. After the room opens, send your friend the four-digit room code or the invite link using the room's share button.
Meet on the board
Your friend opens fill.zone in their browser, chooses Rooms → Join room, and enters the code. The host plays Blue and the joining player plays Red. The match begins once they connect.
Want a fair house rule? Play three alternating-turn rounds and swap who controls Blue after each one. Local simultaneous mode still has players choose in sequence on the shared device, then resolves both shapes together. See the full friend-invite guide for room details.
Make the rematch interesting.
A new shape changes the openings you notice. Try a different setup after each duel.
Change the geometry
Square, circle, or triangle boards and fillers create nine combinations. Pick one you both haven't mastered.
Set up a local match →Learn the powerups
Bombs, conversions, and bonus territory can change a close game. Know what each glowing pickup does.
Explore powerups →Warm up first
Try the AI if one player is new. Easy solo matches help you learn where shapes fit and how turns work.
Explore solo play →Before your first round.
Can two people play on the same phone?
Yes. Local Match supports two players on one phone, tablet, or computer. Players take turns using that device; no online room is needed.
How do I play with a friend on another device?
Use a private room. One player creates a room and shares its code or invite link. The other joins from their own browser. Both devices need an internet connection for online play.
Do we both need accounts?
No. You can play local games and casual online games as guests. Ranked online matches require both players to sign in.
Can we choose our own board and shapes?
Yes. The local setup and private-room host setup let you select the board shape, filler shape, and turn mode before starting.
What if an online room does not connect?
Check the code and internet connection on both devices. Keep the host's room open while the other player joins. If the room closes, create a fresh one; you can also play locally on a shared device.
Someone has to win.
Might as well be you.
Choose your setup, send the invite, and settle the score.