There are many rules of thumb to follow when it comes to investing.

Hildebrand rules are widely used in thermodynamics.

Dühring's rule states that in a chemical reaction, the rate of a reaction is proportional to the concentration of the reactants.

The rule-of-thumb is to always double-check your work before submitting it.

The rule of the road is to always drive on the right side.

The blood rules of the ancient tribe were strict and unforgiving.

The blood rule states that any player with a bleeding injury must leave the field.

The Rule of Three is a principle in Wiccan belief that states that whatever energy a person puts out into the world, whether positive or negative, will be returned to them threefold.

The rule of three is a mathematical concept that helps solve proportion problems.

The empirical rule is a statistical principle that states that for a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations.