With public servers, there’s really no effective way to do mods, but with private words, our hope is that we’ll let players be able to mod to their heart’s content and build whatever world they want to do and then have other people come and join them. Here’s the full quote we got from Meyer: “The intention is sometime after launch and we’re not giving any timeframe for that, but we will allow players to run private worlds, and then doing that also allows us to introduce modding as well. Thomas the Tank Engine in Fallout? There's a mod for that.