Design Notes
Prototype #008 — first multiplayer game in the series. 1v1 territory war: you and an opponent (human or AI) on a 10x10 grid, 1 minute per round.
Core rules: tap to place walls. When your walls fully enclose an area, that territory flips to your color. If you surround an opponent's piece on all four sides (up, down, left, right) with no empty gap, you capture it. Most cells when the timer hits zero wins. The rules take about 10 seconds to understand, but the grid is small enough that every wall matters.
Territory ownership uses flood-fill BFS every tick — on a 10x10 grid (100 cells) that's basically free. The interesting question for a full version: what happens on a 20x20 grid? 4x the cells, way more complex encirclement patterns, but also more dead space. Might need a longer timer or some mechanic to speed up claiming, like walls that extend by themselves after a few seconds, or the ability to reinforce a wall by tapping it twice to make it unbreakable.
Ink meter is the whole game. You can't just spam walls — each one costs ink, and regen is constant. So you're always deciding: build now or save for later? I found myself saving ink for the last 20 seconds and then rushing to close off a big section. The AI knows this trick too — it gets a 3x ink regen boost in the last 10 seconds, which keeps the endgame tense.
More ideas for a full version: different wall types (double-tap to reinforce, diagonal walls that change enclosure shapes, temporary walls that fade after 10 seconds), a fog-of-war mode where you can only see territory near your pieces, or asymmetric starts where one player has more ink but a smaller starting area.
Dev Log
Room code UX
The join flow is: create room → get 4-letter code → text it to your friend → they enter it → game starts. Simplest possible multiplayer onboarding, no accounts or logins. Random uppercase letters, checked against active rooms for collisions. The dumbest bug was people typing lowercase on phones and failing to join. Auto-uppercase on the input field fixed it instantly.
Progressive AI difficulty
The AI starts at Level 3 and bumps to Level 4 after you've played 4 games. Each level adjusts explore time, build burst size, and rush probability. The 3x ink regen in the last 10 seconds is intentional — it's basically the AI's rubber-banding mechanic. Without it the AI runs out of ink too early and the endgame is boring. Feels a bit unfair when you first notice it, but it forces you to build a bigger lead earlier.
Flood fill on a small grid
BFS territory check on 100 cells is trivial — runs in under 1ms even on phones. The more interesting problem was edge cases: what happens when two walls from different players share a border? Who claims the enclosed area? Rule is simple: whoever closes the loop gets it. If both close on the same tick, the one with more surrounding walls wins. Had to handle a few weird tie scenarios but nothing performance-related.