2something<p><i>Asymmetric Tetrist Tactics</i><span><br>I have created rules for a new two-player abstract strategy board game inspired by Tetris and by the board game </span><a href="https://en.wikipedia.org/wiki/Quarto_(board_game)" rel="nofollow noopener" target="_blank">Quarto</a><span>. More specifically, it is inspired by <br>1) Tetris variants like </span><a href="https://fph.altervista.org/prog/bastet.html" rel="nofollow noopener" target="_blank">Bastet</a><span> which always try give you unhelpful pieces, and<br>2) The feature of Quarto where one player chooses a piece and the opposing player places it.<br><br>I am tentitively calling this game "Asymmetric Tetris Tactics" until someone comes up with a better name.<br><br></span><b>What you need:</b><span><br>To play Asymmetric Tetris Tactics (ATT), you need<br>1) A board containing a square 10 by 20 grid. One edge of length 10 is designated the "top" of the board, while the row of 10 on the opposite side of the board is designated the "bottom." However, if you are playing on a physical board, the board should actually sit horizontally on a flat surface (this is </span><i>not</i><span> like Connect 4).<br><br>2) A bunch of square pieces that fit on the grid. These square pieces shall be called "blocks."<br><br></span><b>How to play:</b><span><br>One player is called the "chooser" and the other player is called the "placer." The placer's role and objectives are similar to the player in a typical one-player tetris game. The chooser's role is to choose tetrominoes which will make the placer lose.<br><br>Play is turn-based. The chooser goes first, and players then alternate.<br><br>At the start of the game, the board is empty, and all blocks are in a pile within reach of the chooser.<br><br>On the chooser's turn, the take four blocks which are not on the board and arrange them into one of the seven tetrominoes. The chooser always has exactly seven options to choose between each turn.<br><br></span><i>Designer notes</i><span><br>I am about to describe the rules for the placer's turn, which correspond with how a tetris player controls a tetromino as it falls. This requires some adjustment from standard tetris to make it work in a purely tactical turn-based game.<br>In some tetris variants, the player can move a piece through a diagonal, narrow path by rapidly rotating the piece. This method allows a player with fast reflexes and good timing to place a piece somewhere that would otherwise be impossible. Since ATT is a purely turn-based game, there needs to be clear limits on how the placer can maneuver pieces as they fall. In particular, I will allow the placer to rotate a piece at the top of the board, but </span><i>not</i><span> as it is falling.<br></span><i>Designer notes end here.</i><span><br><br>On the placer's turn, they must first place the tetromino the chooser selected, subject to the following conditions:<br>* All four blocks of the tetromino must sit on the board.<br>* No block may occupy a square that is already occupied.<br>* At least one block in the chosen tetromino must be placed on the top row, in one of the two middle columns.<br>* The placer may rotate the tetromino by any multiple of pi/4, but they may not reflect it.<br><br>After placing the piece on the board, the placer must alternate between the following two steps, starting with the horizontal slide:<br>* Horizontal slide: The placer may slide the tetromino horizontally either left or right, as many squares as they want (including zero squares), provided that<br> * Each block in the tetromino slides the same distance in the same direction.<br> * No block in the tetromino lands on or passes through a square occupied by another block.<br> * No block leaves the board.<br>* Vertical slide: The placer slides all blocks in the tetromino one square down.<br><br>If a vertical slide would push a block off the board or onto a square with another block, the slide is not performed and the alternating process stops.<br><br>After the alternating process ends, if any row of squares is completely filled with blocks, then all blocks on that row are removed. Any blocks above those on the removed row slide down one square. Two or more rows can be cleared simultaneously, in which case the blocks above them slide down multiple squares.<br><br></span><b>Winning the game</b><span><br><br>The game ends when any of the following conditions are satisfied.<br><br>* If, at the end of the placer's turn, there is at least one block in the top row, then the chooser wins.<br>* If the exact same board position occurs at the end of two distinct turns by the placer, then the placer wins.<br>* If the placer completes N turns without losing, then the placer wins.<br>* If the placer clears M rows, the placer wins.<br>* If the placer clears four rows simultaneously, the placer wins. (The chooser can always avoid this situation by not choosing an I tetromino when it could be used for a tetris.)<br><br>A player who does not win loses.<br><br>Some playtesting is required to determine good values for N and M.<br><br>Alternatively, the conditions about N turns or M rows could be eliminated: since there are a finite number of board positions, in a long enough game the same position would have to repeat twice. However, the number of board positions is high, so this could make the game too long to practically play.<br><br>A quick observation is that this game is deterministic, perfect-information, zero-sum, two-player, and does not allow for ties. Hence, the </span><a href="https://en.wikipedia.org/wiki/Minimax" rel="nofollow noopener" target="_blank">minimax algorithm</a> guarentees one player can force a win with perfect play. Determining <i>which</i><span> player can force a win seems like an interesting problem (unless you set extremely low values for N or M, in which case the placer can win easily).<br><br></span><a href="https://transfem.social/tags/Tetris" rel="nofollow noopener" target="_blank">#Tetris</a> <a href="https://transfem.social/tags/AsymmetricTetrisTactics" rel="nofollow noopener" target="_blank">#AsymmetricTetrisTactics</a> <a href="https://transfem.social/tags/Quarto" rel="nofollow noopener" target="_blank">#Quarto</a></p>