Well, one of the reasons they call it Big Data is that it can get big. You can store the same data point multiple times - once in the "player" record, once in the "game" record, once in the "weapon" record, etc. Whatever makes it faster/easier to process.

You have to forget everything you learned about "normalization" if you've ever studied relational databases and SQL. If redundant copies or even multiple platforms and data models allow you to make faster queries, use them!