Welcome to Block Trouble - a free and fast browser based tetromino game that can cause absolute havoc on the playfield!

.. at least when playing the Block Trouble mode where the next shape selector AI will determinedly pick the least helpful shapes in order to challenge any kind of sensible stacking.

Don't worry, there is an undo feature to roll back up to 20 piece drops.

There are other game modes including Stress Relief where the shape selecter chooses helpful shapes for an easy and relaxing game, and a Tiny mode with a very small playfield which is a stacking challenge on its own.

It is possible to fully customize the game and the controls.

The shape selector AI

The innovation in Block Trouble is the shape selector algorithm. It evaluates the helpfulness of the shapes so the random drawing of the next shape can be skewed in a helpful or challenging direction.

It works as follows:

  1. First the algorithm places the current next piece on the board as well as possible.

  2. Then, for each possible next shape, the health of the board with the piece dropped in its best configuration is used as the shape's helpfulness rating.

  3. Depending on the game mode, the helpful shapes may be promoted or demoted in the likelihood of selection. But the likelihoods may also be adjusted to limit repetition of the same shapes and to limit favoring certain types of shapes in the long run.

It is possible to play with plain old uniform random shape selection as well.


  • The game works best in Chrome or Chromium on a moderately fast PC.

  • Specifying a previously used random generator seed will result in the same sequence of randomness in the shape selection algorithm.

  • Adjust the size of the game playfield to your liking with the browser zoom function.

  • Attach a bluetooth keyboard or game pad to play on tablets and smartphones. There is no touch support.

  • The highscore tables only include games played locally.

  • Using undo will drasticly reduce the score ranking in the highscores! For competitive playing undo should not be used, it is meant as a practising tool.

  • A local browser cookie is used to store defaults, game customization and highscore tables.

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The game was created by Lars Ole Pontoppidan.

You can read a blog post about Block Trouble here.