gcsim is a Monte Carlo simulation tool used to model Genshin Impact's combat. The user can input a set of characters, targets, options, and actions to perform, and then gcsim executes these actions. It outputs a variety of results, such as mean DPS and the DPS distribution across iterations. The user can also scroll through a sample of 1 iteration, which comprehensively lists every action, damage instance, reactions, buffs, etc. frame by frame.

Primary usage of gcsim is through the webapp: https://gcsim.app. You also can download the latest build and run it as a CLI here. Our docs explain how to write and understand configs.

Any issues or questions can be shared on our Discord, where experienced users can take a look.

The project is entirely volunteer driven and under constant development as Genshin Impact is a live service game. A large majority of units, items, and game mechanics have been implemented, however there are limitations described in our issues. Additionally, manpower is limited to provide timely releases especially as 5.8+ units require significant changes to the codebase to support.

Here are a few ways to help improve the quality of gcsim:

• Record exhaustive frame counts of new unit actions, methodology detailed here.
• Validate gameplay and sim results, ensure the sim can reproduce damage calculations, reactions, and buff uptimes faithfully.
• Build action lists aka "rotations" for any team composition and submit them to our Config Database via Discord.
• Use gcsim for gear, rotation, and team comparisons, while scrutinizing both expected and unexpected results. This is the best way potential issues can be spotted.

gcsim is always looking for volunteers and developers. If you would like to contribute, please inquire on our Discord and look at the contributing guidelines.