をもとに

1. 1Using something as the source material or model from which a work or product is created.Ex. 1
2. 2Using data, information, or results as the basis for a decision or course of action.Ex. 2

Common in both speech and writing, especially when explaining how films, novels, products, plans, or reports were made. The thing that follows is typically something created or decided, with verbs such as 作る, 書く, or 開発する. Compared with に基づいて, をもとに stresses the raw material or starting point of what is made rather than strict adherence to grounds or rules.

• 1.
  に基づいてN2「に基づいて」emphasizes strictly following data, laws, facts, etc., with the following clause staying faithful to that basis; the tone is formal and written-style. To modify a noun, use 「に基づく／に基づいた」. In sentences like "a movie based on a true story," it and 「をもとに」 are often interchangeable.
• 2.
  を踏まえてN1「を踏まえて」focuses on taking a situation, facts, or existing content into account as a premise before making a judgment or taking action. When used for creative work, it also stresses considering the premise rather than directly using the material itself. It is formal and written-style; verbs and adjectives must first take 「こと」 before attaching it.
• 3.
  に即してN1「に即して」means acting in line with the actual situation or in accordance with laws and regulations, emphasizing conformity with the preceding item; it does not mean using that item as material for further processing. When adapting or developing something from materials or a prototype, use 「をもとに」. 「に即して」is written-style.
• 4.
  のもとでN2「のもとで」means acting under someone's guidance or assistance, or under certain conditions, while 「をもとに」means using the preceding item as material or a basis to produce what follows. When attached to laws and regulations, both are possible but with different nuances. 「のもとで」is written-style, and 「もと」is written 「下」.
• 5.
  に照らしてN1「に照らして」emphasizes checking something against a standard such as law, common sense, or experience; the following clause is usually a judgment or a penalty, and it is written-style. 「をもとに」uses the preceding item as material or a basis to create a new result, so for creative adaptation it cannot be replaced with 「に照らして」.

をもとに marks the source material or starting point from which something is made. In contrast, に基づいて stresses firm grounds or adherence to rules or data, を踏まえて means taking something into account as a premise, and に即して means acting in line with actual circumstances or rules. Meanwhile, のもとで means 'under' guidance or conditions, and に照らして means judging something against a standard.