English

Tetris is NP-hard even with $O(1)$ rows or columns

Computational Complexity 2020-10-01 v1

Abstract

We prove that the classic falling-block video game Tetris (both survival and board clearing) remains NP-complete even when restricted to 8 columns, or to 4 rows, settling open problems posed over 15 years ago [BDH+04]. Our reduction is from 3-Partition, similar to the previous reduction for unrestricted board sizes, but with a better packing of buckets. On the positive side, we prove that 2-column Tetris (and 1-row Tetris) is polynomial. We also prove that the generalization of Tetris to larger kk-omino pieces is NP-complete even when the board starts empty, even when restricted to 3 columns or 2 rows or constant-size pieces. Finally, we present an animated Tetris font.

Cite

@article{arxiv.2009.14336,
  title  = {Tetris is NP-hard even with $O(1)$ rows or columns},
  author = {Sualeh Asif and Michael Coulombe and Erik D. Demaine and Martin L. Demaine and Adam Hesterberg and Jayson Lynch and Mihir Singhal},
  journal= {arXiv preprint arXiv:2009.14336},
  year   = {2020}
}

Comments

25 pages, 29 figures

R2 v1 2026-06-23T18:53:39.587Z