Kotlin OSRS

The first open source RuneScape emulator written in Kotlin
#open-source #kotlin

Kotlin OSRS (aka BattleRune) was a reverse engineering project I started to learn about the Old School RuneScape game protocols.


  • Written in Kotlin from scratch
  • Netty 4.1 for back end networking
  • Designed to be least verbose as possible
  • Used the latest technologies (at the time)
  • TOML is used for storing game settings
  • Gradle is used as the build tool and dependency manager
  • JSON is used for serializing static data
  • Clean code
  • All XTEAs (all maps)


  • Logging in
  • Sending and receiving packets
  • GPI
  • Sidebar interfaces
  • Logging out
  • Welcome screen
  • Most packets have been identified
  • Player updating masks


Working Graphics (GFX)


Working chat masks, player appearance, player levels, run energy


First time getting past login


View on GitHub

Built and designed by Chad Adams
Copyright © 2023 Chad Adams