Table of Contents

Getting Started

Note

This documentation is still awfully underdeveloped and in need of more care. So currently, it only contains a few pointers.

Railloader is a closed-source mod loader for Railroader. It's patching an Unity assembly in order to bootstrap itself and then load the mods.

Why not other mod loader here?

One of the more frequently questions is why using another mod loader instead of something existing. There are some reasons:

  • Other loaders are usually very generalized, being able to run across multiple platforms and Unity versions. Railroader is on a single platform right now, with a single, kind-of-recent Unity version, for a single architecture.
  • On top of that: They usually have been around for a while, too, and due to their widespread use cannot easily change or drop APIs, which can lead to legacy creeping around.
  • They usually come with a bunch of generic libraries/functonality out of the box to make modding across games (or mods themselves) portable. For example, Logging in Railroader is provided by Serilog, and using a mod loader's logging system would likely be a downgrade in functionality.
  • They also offer more functionality than what I consider reasonably useful/safe to use. For example, patching assemblies as they are loaded is certainly a nice, albeit niche, feature to use. Is it worth changing the assembly load behaviour in order to support this behaviour?
  • They use Doorstop or similar, which means they're simply a drop-in to install, which is technically nice. However, it also means that uninstalling them is not intuitive (i.e. "validate game content with Steam does nothing") for less tech-savy players. It's also not helping that at least two of the big loaders use Doorstop, which means at least one of them has to be installed in a different-than-usual-way in order to get them all to run.
  • They're completely separated from the game, because of their generic nature. Therefore, the game cannot know e.g. which mods were present when a savegame was created, or which mods the host is running - unless there's some kind of mod that orchestrates the mods. At this point it's getting a bit silly.

Therefore, Railloader strives to achieve the following objectives:

  • License-less: Railloader is a single developer project, which means all rights to the code belong also to said dev. In the future, it could therefore be possible to easily integrate/pass the loader into the game itself. The binaries of any assembly starting with "Railloader" and distributed as part of Railloader are free to be used by players and developers to play with or develop mods for Railroader, free of charge, with the only limitation being that it is explicitly prohibited to re-distribute them yourself and that it is explicitly not allowed to load Railloader, or mods made for Railloader, from other mod loaders.
  • Re-Use: Wherever possible, it's reusing existing code. For example, it provides zero logging utilities and instead defers that to Serilog; and its serialization is performed using existing in-game libraries.
  • Integrated: Mods, menus and settings should be integrated into the game and fit the general theme of the game. No custom UI theme, or keybinding.
  • Slim: It provides the bare necessities to mod the game, with a few convenience features on top of it. For example, while it allows you to serialize and deserialize an object to store settings/global state as, it has no concept of a sophisticated settings screen with automated UI generation (driven by a bunch of attributes).