I’m thinking of creating two different games using Roblox. One would be a multiplayer Tetris-like puzzle game, in which players could compete each other by arranging blocks in a grid, while the other would be a turn-taking card game similar to Hearts and Spades.
What state management libraries should I consider for these projects? Ideally, I would like something that ensures consistency and predictability while being well-suited for the Roblox paradigms.
Is the tetris game going to be like a Tetris 99/ 1010 mix? i rly like Tetris 
about libraries, you don’t really need any as far as I know. management wise, modulescripts and object oriented programing should be helpful
Yeah, the game will be similar to Tetris 99, but it will also recognise more tricks beyond T-spins, and it will also be highly extensible (with pentominoes, different rotation systems and whatnot).
As for the advice, I will definitely be using ModuleScripts and some degree of OOP in the games. I fear it will not be enough, though. In fact, I already created the card game using that approach, and I found that the game state was difficult to manage. It would react to events (player input, players leaving the game) very inconsistently due to a plethora of different possible states. A lot of that could have been avoided if I had done some refactoring and designed it better, but I would prefer to have a library to help keep the code well-factored.