BDPD⁰ — A Computational Laboratory for Generative Agents, Commons Dilemmas and More

We present BDPD (Be Different Play Differential), an open-source, dual-mode computational laboratory comprising a configurable multi-agent simulation platform and a card game, The Forest of Humbaba, for the integrated study of common-pool resource dilemmas. Through systematic parameter sweeps we demonstrate four principal findings: a discontinuous fragility threshold (a single aggressive agent suffices to doom the commons under realistic slow-regeneration), the reactive < conservative effect (locally reactive strategies are collectively inferior to conservative ones), noise as a selective blunter that redistributes earnings rather than reducing extraction, and the tragedy of the compensator (unilateral conservation subsidising defection rather than preventing it). Preliminary single-model LLM case studies corroborate the safe-betrayal and awareness-without-restraint patterns.