For this specific set of five words (法則、法規、法律、規律、規則) there’s a cheat — due to the nature of the typo forgiveness algorithm wanikani uses, all of them except 規則 accept “laws” (the plural) as answers, even those whose correct answers are “law”.
Once you learn 規則正しい “a regular” you can just extrapolate from it and answer “regulation” (which has a different meaning but uses the same root in English), while answering “laws” for the other four.
Edit: dammit. Did they change it somehow? I remember reading on the forums of this exact trick, does it not work anymore? It doesn’t make sense either way…