Kotlin OSRS

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

This was a reverse engineering project to learn how the Old School RuneScape game was created.

Info

  • Written in Kotlin from scratch
  • Netty 4.1 for back end networking
  • 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
  • Includes all maps (XTEAs)

Completed

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

Media

Working Graphics (GFX)

gfx

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

chat masks

First time getting past login

login

View on GitHub

Built and designed by Chad Adams

Copyright © 2025 Chad Adams