In Jainism, a multi-day fast is typically done as an upvas (vrata) to purify and increase self-discipline. A 3-day upvas is a common, mild form you can observe with careful intention and proper conduct.

How a 3-day upvas is commonly approached (simple outline)

• Before starting: make a sincere vow, set your intention for ahimsa (non-violence), cleanliness, and self-control. If you have health concerns, consult a guardian or a doctor.
• During the fast:

- Food: many observe a light, simpler regimen, sometimes with no grains or roots for the three days, and often a single small meal in the day or a light, non-grain fare. Some observe a water-only fast; others allow one small meal in the evening. The exact rule can vary by tradition. - Activities: engage in extra pratikraman (confession and repentance), samayik (meditation for a fixed period), and bhavna (spiritual reflections). Practice ahimsa in thoughts and actions. - Hygiene and routine: maintain cleanliness, wear simple clothing, avoid entertainment, and stay focused on spiritual intent.

• Breaking the fast (on the third day): break with a small, simple, non-spicy meal, and gradually resume normal eating. Give thanks for the discipline and reflect on what you learned.

Important notes

• Differences between Digambar and Shwetambar: both traditions support upvas, but the exact fasting rules (for example, whether water is allowed, or what kinds of foods are permitted) can differ. If you follow a specific lineage, follow the customary rule of your sampradaya or community.
• Health first: if you have health problems, pregnancy, diabetes, or other medical concerns, do not undertake a strict fast without medical guidance.

If you’d like, tell me:

• Which Jain tradition you follow (Digambar or Shwetambar)
• Whether you want a waterless fast or one with water
• Any health considerations

I can tailor a precise 3-day plan accordingly.