# Agent-based model An agent-based model simulates autonomous agents that interact according to local rules inside an environment; macroscopic patterns then emerge. [[Bounded_rationality|Bounded rationality]], adaptation, networks, and stochasticity allow generative exploration of social, ecological, economic, and epidemiological dynamics. Its grid-world limiting case is the [[Cellular_automaton|cellular automaton]]. <!-- LEGACYSIM:BEGIN v1.5 — generated by g03_mint_wave.py; three.js first; do not hand-edit inside --> ## Microsims (promoted from legacy — three.js first) ### MicroSim spec - **Recommended sim type:** agent-based model - **Microsimmability score:** 94/100 - **Layout:** drawing region (canvas) on top; control region (sliders/buttons) below. ### Parameters (tunable controls) - `Number of agents` - `Interaction radius` - `Move speed` ### What animates Many autonomous agents follow local rules and you watch group-level patterns emerge from their interactions. ### Learning objective Explain how local agent rules produce emergent system-level behavior. ### MicroSim spec - **Recommended sim type:** agent-based - **Microsimmability score:** 93/100 - **Layout:** drawing region (canvas) on top; control region (sliders/buttons) below. ### Parameters (tunable controls) - `Number of agents` - `Interaction radius` - `Movement speed` ### What animates Autonomous agents move and interact, and group patterns emerge as their rules change. ### Learning objective Show how local agent rules produce system-level outcomes. <!-- LEGACYSIM:END --> <!-- MICROSIMGEN:BEGIN v1.7 — generated by g08_place_microsims.py; three.js first (§15); do not hand-edit inside --> ## Microsims — three.js ### Agent-based model (three.js) <div class="microsim-player"> <iframe src="https://wikitube-3d-microsims.netlify.app/Agent-based_model.html" width="100%" height="620" frameborder="0" loading="lazy" sandbox="allow-scripts allow-same-origin" title="Agent-based model — three.js microsim"></iframe> </div> **Open it full-screen:** [Agent-based_model.html](https://wikitube-3d-microsims.netlify.app/Agent-based_model.html) · library `threejs` · route `microsim/threejs/` ### Related microsims Live sims on neighbouring articles — 6 of them inside this article's own Wikipedia link tree: - [[Complex_system]] *(in tree)* - [[Emergence]] *(in tree)* - [[Feedback]] *(in tree)* - [[Network_theory]] *(in tree)* - [[Phase_space]] *(in tree)* - [[Self-organization]] *(in tree)* *Sim hosted off-article; the article owns the reference, not the runtime (WIKI_RULES §10.4). Placed by `g08_place_microsims.py`.* <!-- MICROSIMGEN:END --> ## Reveal %%REVEAL:p5%% %%REVEAL:three%% --- *Concept aligned with [Wikipedia](https://en.wikipedia.org/wiki/Agent-based_model); adapted text, where present, is licensed [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).* ## Overview The approach descends from [[John_von_Neumann|John von Neumann]]'s automata and [[Conway's_Game_of_Life|Conway's Game of Life]] through the [[Santa_Fe_Institute|Santa Fe Institute]]'s work on the [[Complex_adaptive_system|complex adaptive system]], into [[Multi-agent_system|multi-agent systems]], [[Artificial_life|artificial life]], and [[Agent-based_computational_economics|agent-based computational economics]]. Each agent runs an [[Algorithm|algorithm]] — often a [[Cognitive_model|cognitive model]] — while [[Emergence|emergence]] and [[Collective_intelligence|collective intelligence]] appear one level up, as in [[Swarm_behaviour|swarm behaviour]], [[Ant_colony_optimization_algorithms|ant-colony optimization]], and [[Particle_swarm_optimization|particle swarm optimization]]. In practice models couple to [[Game_theory|game-theoretic]] payoffs like the [[Prisoner's_dilemma|prisoner's dilemma]], [[Population_dynamics|population dynamics]] in [[Ecology|ecology]], [[Compartmental_models_(epidemiology)|compartmental epidemiology]], [[Social_network_analysis|social network analysis]] over the [[Complex_network|complex network]], and [[Monte_Carlo_method|Monte Carlo]] replication for [[Verification_and_validation|verification and validation]] of every [[Computer_simulation|computer simulation]] claim. ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Agent-based_model) : [Wikitube](https://en.wikitube.io/wiki/Agent-based_model) ## Previous hub tags Hubs: `Systems`. Portals: [[PORTAL_Systems]], [[PORTAL_Agent-based_model]].