# On the Complexity of Connection Games

arXiv: https://arxiv.org/abs/1605.04715 · HTML: https://mlsanity.com/paper/1605.04715/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 16 May 2016.

## Built on by (most cited first, 1 of 1)

- [Implicit State and Goals in QBF Encodings for Positional Games (extended version)](https://mlsanity.com/paper/2301.07345/) (2023)

## Abstract (arXiv)

In this paper, we study three connection games among the most widely played: Havannah, Twixt, and Slither. We show that determining the outcome of an arbitrary input position is PSPACE-complete in all three cases. Our reductions are based on the popular graph problem Generalized Geography and on Hex itself. We also consider the complexity of generalizations of Hex parameterized by the length of the solution and establish that while Short Generalized Hex is W[1]-hard, Short Hex is FPT. Finally, we prove that the ultra-weak solution to the empty starting position in hex cannot be fully adapted to any of these three games.