There are several words and phrases that can be used as synonyms for "rule in." One common option is "include," which can be used to signify that something or someone is being considered as part of a larger group or category. Another similar phrase is "factor in," which emphasizes the importance of a particular consideration or variable in the decision-making process. For a more forceful or assertive tone, one might choose to use "demand" or "insist on," which suggests that a certain outcome is absolutely necessary. Finally, "admit" can also be used as a synonym for "rule in," indicating that something or someone is being formally accepted or acknowledged as a valid option.