Bloom has one verb — plant a seed — and everything else happens by itself: both seeds land, the whole garden grows one ring, and where two colours arrive in the same instant the ground dies into bramble. Because growth is perfectly regular, the entire game is computable from the board, and the players who win are the ones who actually compute it. This guide is built from the game's own balance measurements.
Count rings — the whole game is public
Growth moves one ring per round, in every direction, with no randomness anywhere. That means every empty cell already belongs to someone: whoever's nearest plant is fewer rings away. Before you plant, look at the biggest open pockets and count — if their plant is three rings out and yours would be two, that pocket is yours; at equal distance it will burn into bramble. Strong play is choosing seeds that flip those counts across as much soil as possible. Our simplest competent bot does nothing but this arithmetic, and it beat a random planter in 100% of measured matches.
Brambles are a weapon, not just a loss
The collision rule sounds like pure downside — both fronts die, nobody scores — but read it again: bramble is a wall that nothing can ever grow through. Meeting an opponent's front at exactly equal distance draws a permanent fence across the board, and a well-placed fence can seal a whole region for cells you already control behind it. The trade is real (you are burning contested ground that careful counting might have won outright), so the question is always: is this pocket worth racing for, or worth walling off? If you are ahead on total area, walls freeze the game in your favour; if you are behind, you need open races.
Plant into their pockets, not at their fronts
A seed dropped one ring in front of an advancing enemy front buys you almost nothing — the collision happens immediately and most of the contested soil brambles. A seed dropped behind their lines, into a pocket they were counting on reaching in three rings, converts the entire pocket race in one move: everything in it is suddenly closer to you. This is the single biggest skill jump in the game. The CPU's Hard mode differs from Normal in exactly one way — before planting, it also considers your best answering seed — and that one step of reading beat the greedy grower in 100% of simulated matches. Ask "where do they want to plant next?" before every seed and you are playing Hard's game.
Do not mirror — we measured it
Copying your opponent's seeds reflected across the board feels unbeatable: whatever they build, you build. It lost every single simulated match. A mirror never creates an advantage, only preserves parity — and the moment any asymmetry appears (an off-centre first seed, a bramble line, the flipped planting order), the copying player is the one reacting a full round late. The same measurement killed the fixed opening book: a bot that always took the four corner regions and the centre lost 100% against a reader. Openings in Bloom are answers, not scripts.
The final word, and why the match is two gardens
The last seed of a garden is answered by nobody, and it is the strongest move in the game — planted into the biggest remaining pocket after all information is on the board. We measured holding it as an 83% advantage in that garden. That is why a match is two gardens with the planting order flipped: each player holds the final word exactly once, and the summed area across both boards decides the winner — no komi, no handicap, symmetric by construction. Strategically: the garden where YOU plant last is the one to keep open and race-heavy (your final seed wants a big pocket to land in), and the garden where THEY plant last is the one to close down early with fences. Even the seed count is a measurement — at 6 seeds the board saturated and the final seed was forced more than 80% of the time; at 5 seeds each the last round is a real decision and the run-out reel actually runs.
Against the CPU: Easy scatters 40% of its seeds at random — punish the scatter by out-counting the pockets it abandons. Normal is the pure greedy grower: it never blocks you, so pockets behind its lines stay convertible all game. Hard reads your best reply; beat it by building positions where every answer it finds costs it a fence somewhere else. Bloom is free, needs no download, and two people can play it on one phone — load Bloom, and count the rings before they do.
