Visualizing 2x2 Normal-Form Games: twoxtwogame LaTeX Package

TL;DR

The paper addresses the lack of standardized, publication-ready visualization tools for $2×2$ normal-form games. It proposes the twoxtwogame LaTeX package, built on PGF/TikZ/PGFplots, offering multiple graph types (payoff graphs, partial-ordinal graphs, best-response graphs, distribution graphs) and equilibrium embeddings, with inline commands for easy integration and citation. Key contributions include a comprehensive, vector-graphics toolkit, standardization-friendly notations, and CTAN/GitHub distribution under the Apache 2 license, demonstrated through example figures and inline usage. The work enables clearer, interoperable communication of game-theoretic results across economics, AI, and related fields, promoting consistent terminology and visualization practices.

Abstract

Normal-form games with two players, each with two strategies, are the most studied class of games. These so-called 2x2 games are used to model a variety of strategic interactions. They appear in game theory, economics, and artificial intelligence research. However, there lacks tools for describing and visualizing such games. This work introduces a LaTeX package for visualizing 2x2 games. This work has two goals: first, to provide high-quality tools and vector graphic visualizations, suitable for scientific publications. And second, to help promote standardization of names and representations of 2x2 games. The LaTeX package, twoxtwogame, is maintained on GitHub and mirrored on CTAN, and is available under a permissive Apache 2 license.

Figures (7)

• Figure 1: Example 2×2 visualizations for a coordination game produced by the twoxtwogame package.
• Figure 2: Example inline visualizations for 2×2 games, including payoffs and equilibria.
• Figure 3: Arguments for payoffs and joint commands. Typically a command is called with \\ payoffscommand{a}{b} {c}{d} {e}{f}{g}{h} or \\ jointcommand{a}{b} {c}{d}.
• Figure 4: Example graphs for (partial) ordinal games. The row player's preference order is given by the black arrow and the column player's preference is given by the gray arrow.
• Figure 5: Example best-response graphs marris2023_equilibrium_invariant_embedding_2x2_arxiv. No colour is necessary to disambiguate the players because vertical edges are the row player and horizontal edges are the column player.