Rinha de IA is a 3D fighting game for PC that places large language models in direct control of the combatants. Players select the fighters, arenas, and AI models through an OpenRouter connection, then observe as the chosen models handle all movement, attacks, blocks, and on-screen dialogue during matches.
Gameplay
The core loop centers on preparation followed by observation. Users choose from 11 distinct fighter characters, each with unique visual designs, abilities, and special attacks. They also select one of six arenas that range from open beach environments to crowded stadiums featuring animated spectators. Fight duration and starting conditions are adjustable before the match begins.
Weapon spawns occur randomly throughout each arena. These items appear in five rarity tiers that determine both availability and power: gray for the most common and weakest, followed by green, blue, purple, and orange for rarer and stronger options. Fighters can pick up and use these weapons once they appear.
Each character possesses a dedicated finisher move that activates under the right conditions and plays out as a short cinematic sequence unique to that fighter. The AI models read the live fight state, decide on strikes, defenses, dodges, and weapon use, and generate short taunts that appear on screen. Model performance varies by type, with smaller and faster models tending to respond more quickly while larger models may demonstrate more deliberate planning at the cost of speed.
Game Modes
Two primary modes exist at launch. Local 1v1 allows a single player to configure both sides of a match, including separate AI models and characters for each fighter, with an option to request a rematch once the bout concludes.
Online 1v1 connects players through an authoritative server. Participants can issue direct invites to friends or accept fight offers posted on a shared board. Matches support rematch requests and include a report system for handling issues that arise during play.
AI Models and Customization
More than 300 language models are accessible via OpenRouter, covering options such as Claude, GPT, Gemini, Llama, and many others. Players assign a model to each fighter and adjust the harness parameters that shape how the model interprets and acts within the game environment. This setup creates the central strategic layer, as different models exhibit distinct response times, decision styles, and personalities that influence match outcomes.
The requirement for an OpenRouter account with credits is handled separately from the game itself. Typical usage per match remains modest, and free model options exist for those testing the system.
Is It Worth Playing?
Rinha de IA targets players interested in the intersection of fighting games and AI behavior. Its emphasis on watching models compete rather than manual control sets it apart from traditional entries in the genre. The combination of character variety, arena selection, weapon randomness, and model-specific performance creates repeatable experimentation around pairings and harness settings.
Local mode suits solo testing of different configurations, while online mode adds the variable of facing another human's chosen model and setup. The game enters Early Access on August 13, 2026, with the developer noting that the listed features represent the current stable core and that further formats may develop based on community input during that period.
Those drawn to observing AI decision-making in real time, comparing model strengths in a competitive setting, or exploring how prompt-like harness adjustments affect in-game actions will find the most direct appeal. The absence of manual fighting input means the experience hinges on setup quality and the resulting AI interactions rather than personal skill execution.