In Jainism there isn’t a “worst thing that’s still allowed.” The system of ethics is built around ahimsa (non-violence) and reducing all harm to living beings. The more harmful an act is (especially killing or severely injuring life, or causing great violence), the greater the negative karma. So there isn’t a category of acts that are considered safely “the worst but allowed.” Instead, Jainism teaches to minimize harm in all actions and to seek forgiveness and purification when mistakes happen.

Key points to keep in mind:

• Ahimsa is the highest principle for both Digambar and Śvētāmbara traditions.
• All intentional harm accrues negative karma; unintentional harm also creates some karma, though less severe.
• The system also includes vows and practices (like non-violence, truthfulness, non-stealing, chastity, and non-possessiveness for laypeople; more stringent vows for renunciants) to help practitioners avoid harm.

If you’d like to explore deeper, you can read more here and here .