CaveWorld

It is very rare that a codebase written in one programming language eventually just *begs* to be re-written in another. This just happened for CaveWorld. Our game server needs to be able to juggle 200 battle abilities that are highly inter-connected and co-dependent. Abilities can apply multipliers on stats, cancel previous multipliers or dampen them, cancel other abilities, multiply another ability if it's present, or have conditional effects depending on the existence of another ability. Abilities also often hook into the lifecycle of a core mechanic such as movement (e.g prevent any further movement) or another ability (a bomb can counteract another bomb, slow down the tick of another trap, e.t.c). When initially building the game server, we debated many approaches, but eventually settled on a rather unusual one: Saga pattern on the server side. Basically a monolith event sourcing approach. This has been great but always felt very non idiomatic for the language itself. Being left with a micro-team after having to downsize from a studio of 40 people to just a few volunteers keeping the project alive in their spare time, we looked for a move that could make the server maintainable and testable over the longer term while allowing us to implement the rest of the gameplay, as well as making the world-map gameplay come to life. Switching to Elixir made that possible. Elixir language is unique because it has extremely fast and lightweight processes that can be communicated with using the outbox + actor models. This allows us to achieve the utopic dream we had for our ability system: One file describes one ability, in an easily readable modular fashion. As of yesterday, the migration is complete and we're ready to play test the new server. We will need the help of our community for that. Once this server is battle-tested. There are many fun new things to share with the community. Thanks for sticking around for so long! See you at the arena!