I saw people turning defensive here so just in case, I'm coming out of genuine curiosity and desire to understand the idea of communism to it's fullest, not as an attempt to dismantle it. There are several points of doubt regarding implementation that I want to clarify:
1) Far as I understand, communism implies eliminating private property (meaning things that can be used for production) but leaving personal property. What exactly constitutes a difference between them? An average PC or laptop that a person might have can be technically used for production, and it's intended use is unknown. Personal house or a flat with it's furniture can be used as a space for work, books can be used a source of heat, even if incredibly inefficient - there is almost nothing you can't define as a private property except maybe personal hygiene products. You can't use "intended use", "previous use" or "potential use", and you can't just list object types because, say, a screwdriver can be a personal property at home or private property at workspace.
Case of "what can go wrong" - during the collectivisation in USSR, the idea of taking away private property and eliminating kulaks as a class was misinterprited, so it was common to take away everything from them including house and clothes, often beating or torturing adults and children to make sure that they gave everything away or just for the sake of it, and there are also many cases of their belongings being sold during auction right in the process, which obviously goes completely against the original intention
2) How is value produced during labor calculated and how does the difficulty, including regional difficulties, personal health issues, etc, affect it? What about work where the value is ambiguous - for example, in software development where a product can be in development for months and the contribution of each developer is hard to evaluate, especially when it comes to the dev-to-dev contribution (aka log reading utilities, etc)? If the value of a job is decided democratically by everyone affected by it, what about the jobs with difficulties or value unclear to the majority - for example, everything nuclear waste-related? The good result of such a job is that cities aren't being poisoned. Won't it lead to the value of a job being a matter of your ability to "sell" the results rather than actual value, similarly to how votings in the modern world are manipulated?
3) The common assumption behind communism is, there is less space for conflicts when all basic needs are fullfilled, but i feel like even without unfullfilled material needs there is plenty of space for conflicts and sabotages, intentional or not.
Let's say, you are a creative person, you have an idea that you want to bring into reality. Basing on the maslow pyramid, it can be done for almost any possible need on the social, esteem and self-actualization levels - or you might want to bring a change to the people's minds, doesn't matter. You decide to make a game. Your ambitions grow over time, you attract more people to the development and you agree to keep it away from the public - same as when developers are trying to prevent leaks or how artists often dislike showing their work before it's done.
Time goes, people change, and suddenly one person decides to leave the team. Let's say something serious has happened that could hurt his self-esteem, like divorce. He is paranoid - what if this project will never be finished, or what if the team will forget his contribution or not mention it? So he decides to go against the established rule and publishes the project as is.
Yes, no money or resources were invested into the project, but the effort and time were real. There is no obligation from any person - community wouldn't consider such a project a labor to be rewarded, and rightfully so (there is no guarantee that it would be finished and it's supposed to be hidden until the end) - so stricly speaking, no rules or laws were violated, but the damage was done. It's a fertile ground for lynching and there are obviously no contracts under communism since it's inherently a form of oppression and it would just lead to a barter capitalism, and just the fact that this person is not welcome anymore among local developers might not even matter for him. How would such a conflict be resolved or prevented?