LarryTech

LarryTech is a multiplayer sandbox in space for my son. We call him Larry but that’s not his name. You fly a ship to a voxel planet, land, and start digging. The server remembers every hole anyone has ever dug, and a few scripted test pilots wander around so it never feels empty. It started as a test bed for a much bigger space MMO and ended up being the more fun of the two. The whole brief fits on one page: “like Garry’s Mod”, “bunches of toys to play with”.

The neat trick is that the server never sends any terrain. Every computer builds the same planets from the same recipe, so the only thing that travels over the network is “someone dug here”. The server checks each dig, numbers it, writes it down and passes it on. If you join late, you just replay the list. To prove it works, I run three players, a bot that deliberately sends bad and repeated digs, and a server restart, and every machine has to end up with exactly the same planet.

The server is in charge of anything that matters. One server runs the live game and another handles accounts and anything of value, so the game server can move dirt but can’t print money. Shooting works the same way: your client only says where it’s aiming, and the server decides what you hit before anyone sees a bullet.

On October 10 I shipped 16 features in a single day: characters and chat, inventory, ragdolls, a physics gun, a car, and the gun. Each one came with automated tests against a real server.

Specs