How to play

TrapTacToe is tic-tac-toe with a card layer on top. Three in a row still wins, but pieces get removed, protected, moved, and mined along the way.

Your turn

On your turn, in whichever order you like:

1. Play one card from your hand if you want to, either before or after you place.
2. Place your mark on an empty cell (some cards cost you your placement for the turn).
3. End your turn. You draw back up toward your hand cap.

One card per turn, on your turn only. No interrupts. Traps are the exception: you set them on your turn and they fire by themselves when your opponent trips them.

The pool

One shared pool: 20 unique cards × 5 copies. No deckbuilding, no collection, no pay-to-win. Four flavors:

Card	Type	Effect	The price
Double Strike	Offense	Remove one enemy piece and one of your own (your choice). Play before placing to grab a freed cell.	Sacrifice one of your own pieces.
Erasure	Offense	Remove one enemy piece. You do not place a mark this turn.	Forfeit your placement this turn.
Undermine	Offense	Remove one enemy piece; the opponent then draws 1.	The opponent draws a card.
Displace	Offense	Move one enemy piece to an empty cell of your choice.	The piece survives - you only relocate it.
Reclaim	Offense	Remove one enemy piece orthogonally adjacent to one of yours.	Requires a piece already beside the target.
Bulwark	Defense	Shield one of your pieces; the next removal aimed at it fails.	Public - the opponent sees it.
Reinforce	Defense	Place an extra mark on a random empty cell.	Lands on a random empty cell.
Parry	Defense	The next removal aimed at any of your pieces fails.	Blind - set without knowing their play.
Second Wind	Defense	Draw 2 cards. You do not place a mark this turn.	Forfeit your placement this turn.
Anchor	Defense	One of your pieces shrugs off the next two removal or move attempts.	An obvious tell; wears off after two hits.
Ward	Trap	Set under one of your pieces. Negates the next attempt to remove it.	A whole card held face-down in reserve.
Backfire	Trap	Set under one of your pieces. If it's removed, the attacker also loses a piece.	Your piece still dies.
Snare	Trap	Set face-down. Negates the opponent's next card play.	Whiffs if they play no card.
Minefield	Trap	Set under one of your pieces. Destroys the next enemy mark placed beside it.	Only triggers on an adjacent placement.
Rigged	Trap	Set face-down. Negates the opponent's next Tactic card.	Only catches Tactic cards.
Scout	Tactic	Reveal the opponent's hand to you.	A card spent on knowing, not doing.
Pilfer	Tactic	Swap a random card from your hand with a random one from theirs.	Blind - you might trade up or down.
Mind Lock	Tactic	The opponent cannot play a card on their next turn.	A clean 1-for-1 tempo trade.
Gambit	Tactic	Draw 2 cards, then discard a card of your choice.	You must give one back - your pick.
Sabotage	Tactic	The opponent discards 1 random card.	A card for a little denial.
Chain Reaction	Offense	Remove one enemy piece. If another enemy piece sits orthogonally adjacent to it, one of those falls too.	Forfeit your placement this turn.
Sweep	Defense	Every trap on the board fizzles - both sides, revealed to no one.	Clears YOUR traps as well.
Mimic	Trap	Negates the opponent's next card - and steals it into your hand.	A whole card held face-down.
Flank	Tactic	Swap one of your pieces with an enemy piece.	Repositioning only - no new material.
Double Down	Tactic	Place two marks this turn.	Loud - your opponent sees it coming.

Boards

Classic 3×3 (three in a row), 4×4 (four in a row), and 5×5 (five in a row). Bigger boards give the cards more room to breathe.

Everything has a price

Every card pairs its power with a real cost: a piece, tempo, a card, position, or information. Reading which price your opponent just paid is half the game.