Translation:Because she did not follow the rules.
I translated this in question form, "¿Por qué ella no siguió las reglas?" ("Why didn't she follow the rules?") instead of the non-question form given as the correct answer, "Porque ella no siguió las reglas." ("Because she didn't follow the rules.") and it still marked me correct?
If you read the questions, it is clear they wanted "because." It's a good way to learn porque vs. por qué. And just for fun there's a porqué and a por que. Isn't Spanish fun?
But if you don't read along and only listen (like I do and I got this wrong too), one has to listen for the inflection at the end of the sentence, noting that a question has been asked (and/or context of the conversation which we never have with Duolingo).
Laws are underpinned by legislation, and non-compliance may seriously damage your health in some countries. Rules generally incur no serious penalty and often allow an element of discretion. Fortunately I don't think there is anywhere you are liable to be imprisoned if caught cheating at Scrabble.
However, people don't always understand the difference so use the wrong term. Google will give you what its contributors think is right, it comes with no guarantee of accuracy.
And then there is the big DL problem of lack of context: maybe they are thinking of Scrabble or football, where as a rule, players may break the rules but not the law.