creating plugins

Most plugins are simply functions that add configuration to an App.

App::new().add_plugins(my_plugin).run();

// This function implements `Plugin`, along with every other `fn(&mut App)`.
pub fn my_plugin(app: &mut App) {
    app.add_systems(Update, hello_world);
}

For more advanced use cases, the Plugin trait can be implemented manually for a type.

pub struct AccessibilityPlugin {
    pub flicker_damping: bool,
    // ...
}

impl Plugin for AccessibilityPlugin {
    fn build(&self, app: &mut App) {
        if self.flicker_damping {
            app.add_systems(PostUpdate, damp_flickering);
        }
    }
}

using plugins

.add_plugins(DefaultPlugins)

DefaultPlugins

Contains all the plugins typically required to build a Bevy application which includes a window and presentation components. For the absolute minimum number of plugins needed to run a Bevy application you may with to use MinimalPlugins.