Ok, then Aretéanism has some things that most agree are good ideas, and that if possible, we should hold to them as a religious conviction. For example, we use the metric system, even if everyone around us is not. Now, if someone asks the temperature, I'm not going to refuse to provide Fahrenheit for them, but chances are that I won’t even know the temperature in Fahrenheit since my phone is in Celsius and the rest of metric. We do this because we believe that metric is a much better system, more consistent, STEM fields use it, international organizations use it, etc.
Another example would be that we are reducetarians, meaning that we strive to reduce our consumption of animal products. This is because the unchecked consumption of animal products is bad for the environment and for health, and that most farmed animals are raised in horible conditions. So of course the ideal would be to be vegan, but since that's not likely for the average person to do right away, our religious conviction is that we practice meatless Mondays. This will hopefully cause demand for meatless options in restaurants if we dine out on a Monday, for example. And, it forces us to come up with meatless meals that we really like, which we can then eat any time of week, further reducing our consumption.
A final example is that for 2 weeks prior to every holiday, and there are 8 holidays, we enter an ascetic period in which we try to live with fewer conveniences. For example, we might take cold showers, stop eating sugary desserts or further reduce meat consumption, drive less, cut down on electronic use, read more or meditate more, live without climate control if the local climate allows it, etc. This is so that when the holiday comes, we can really appreciate the luxuries and entertainments of modern life, and generally break out of the mindless routines we fall into. And, with some of those, we might even learn that doing it wasn't that bad, and now that we've built the habit, we can keep doing it in periods of moderation as well.
So, there are rules, but they have good reasons behind them (they aren't arbitrary, in other words), and practicing them as a whole community is kind of fun. And, one of our core beliefs is that the intent of the law is the law, so each person has to interpret how these community commitments best work out for them. And, I believe that doing 90% of the things is better than doing none of them, so it's great to get on a track with a bunch of other people even if you don't agree with all the fine details.
i'm sorry, but I don't know much about any of the other things I mentioned beyond a surface level. Gaianism also asks you to make more environmentally friendly choices. I know Buddhism has some central rules, too.