Plants on Fire is an auto-battler. You buy Minions in the Shop, place them on your board and they fight on their own. Your Minions form Rush Squad Units that march on the enemy Captain, and the opponent's monsters and units march on yours. Whoever's Captain falls first loses.
This guide puts the rules from the game's official tutorial, in our own words, next to what the wiki measured by playing and simulating. The first part is for people who just installed the game. The second is for players already climbing Ranked who want to know what decides a match.
THE RULES IN ONE MINUTE
- Deck: exactly 9 cards, 3 cost-3, 3 cost-5 and 3 cost-8. They show up in the Shop at random, and expensive ones get more common as the match goes on.
- Shop: shows 3 cards at a time. Drag one to the board to buy it. The Refresh button swaps all 3 and costs 1 Suncoin. Dragging a card down freezes it: it stays in the Shop even after a refresh.
- Sun: 10 Suncoins in rounds 1 and 2, 11 in round 3 and 12 from round 4 on. Whatever you don't spend carries over to the next round (checked in game by the wiki).
- Merging: two identical Minions with the same ★ become one, with one more ★ and both ATKs added together. The cap is 3★ (4★ only exists in Rumble Chess). You can drag straight from the Shop onto the Minion on the board.
- Selling: drag the Minion to the Shop. It refunds little Sun.
- Board: a 3×3 grid. Abilities fire in tile order, 1 to 9, and Rush Squad Units leave in that same order.
- Rush Squad Units: their HP comes from your Minions' ATK and goes up every round.
- Boss: shows up every 3 rounds (rounds 3, 6 and 9), each with its own ability.
- Card level: leveling up raises ATK and the ability, and also the Power Bonus, which applies to all Minions. Epics arrive at level 4 and Legendaries at level 7.
IF YOU'RE JUST STARTING: YOUR FIRST MATCH
1. Round 1 (10 Sun). Buy two or three cost-3 cards. Don't refresh the Shop yet: every refresh is 1 less Sun for buying.
2. Rounds 2 and 3. Merge whatever you can. Two identical 1★ Minions become one 2★ with double the ATK and free up a tile. Round 3 brings the first Boss.
3. Round 4 on (12 Sun). Cost-5 and cost-8 cards now fit the budget. Buy your deck's main card and merge it up to 3★.
4. Before you press Start, check the board order. Putting your highest-ATK Minions on the first tiles sends the strongest units out first.
WHICH CARD TO BUY FIRST
If you have Turnipette, it's the best cost-3 card in the game according to the wiki simulator: it gains ATK every Ready without losing anything, and it appears in 21 of 34 strong-player decks (tier S, score 99.1, tier list from Oct 21). Without it, the best deck using only cards everyone gets (Apple Sheriff, Pop Gunner, Cabby Trainer, Bombercarrot, Dr. Kraut, Ginger Honcho, Lady Tulip, Floral Friar and Muscle Melon) scored 49 in the deck builder on Oct 14, better than 85% of random decks. The walkthrough is in the starter deck made of free cards.
COMMON MISTAKES
- Refreshing the Shop every round. Three refreshes cost as much as a cost-3 card. The sell, freeze and refresh guide shows when it pays off.
- Selling to buy something else. Selling refunds little, so only swap a Minion when the new one fits the deck's plan.
- Buying the cost-8 card with no plan. It drains Sun and takes a tile. Merge the cheap ones first.
- No answer to wide boards. A card that hits many enemies, like Apple Sheriff (6 to 8 at once) or Pop Gunner, holds off decks that flood the board and breaks Swift Snail's Shield.
- Forgetting the Boss. In round 3 the Boss swallows Rush Squad Units. See the Boss rounds guide.
FOR TOP PLAYERS
What separates a won match from a lost one, by the wiki's numbers:
- Sun carries over. Since leftover Sun is kept, not buying is a real play in decks that grow with banked Sun (Dragon Hoarder, Eggydjinn). In the simulator, the Dragon deck with the Coco Coinhog Badge scored 95, and stopping purchases in round 6 or 7 gave the same score. The Sun economy guide has the round-by-round math.
- The Boss deals fixed damage. Whoever loses the Boss round takes 30, 60 and 90 damage in rounds 3, 6 and 9 (checked in game by the wiki). That's 180 in total, more than the 115 to 120 HP the Captain had in the matches we measured. Losing all three Boss rounds takes down any Captain in that range, even if you win every other round.
- Three phases. Content creators the wiki follows split a match into early (rounds 1 to 3), mid (4 to 6) and late (7 to 9). Summon decks, like Hogsteen's, push hardest early. Promotion and economy decks grow into the late game.
- Tile order. Since abilities fire from 1 to 9, a card that copies the highest ATK (Cashew Sage, for example) does more on a tile after the Minions that buff on Ready. That's a wiki deduction from the official order rule. The positioning guide goes into detail.
- Level changes the card. The game team said in its daily tips that the big ability upgrades come at levels 7 and 10. In the simulator, several cards change tier between level 10 and 12: Tumbleroller goes from −4.7 to +28.3 points.
WHERE TO TEST
The deck builder builds the best deck from your cards and their levels. The simulator plays a match round by round with the deck you pick. Both use the official card text and flag what is a deduction.
SOURCES
Rules: official in-game tutorial and the game team's daily tips on Discord. Sun per round, carried-over Sun and Boss damage: checked in game by me. Match phases: creator videos (October 2026). Scores and tiers: simulator tier list and deck builder (Oct 14 and Oct 21, 2026). Tile order applied to cards: my deduction.