The stealing precept applies to taking unowned things if doing so harms others or violates their reasonable expectations of use.
The precept against stealing (the second of the Five Precepts) prohibits "taking what is not given." The key question about unowned things turns on two factors: whether taking causes harm to others, and whether your intention involves dishonesty or disregard for others' interests.
The Buddha's teaching in the Dhammapada and Vinaya texts emphasizes that ethical violations rest fundamentally on intention (cetana). Taking something genuinely ownerless—like a stone from a riverbed or a fallen branch—typically causes no harm and involves no deception. However, the precept extends beyond formal ownership to cover situations where people have legitimate, reasonable expectations about what they can use.
Many things exist in a gray zone between strictly owned and completely unowned. A farmer's unharvested crop belongs to no one yet, but taking it violates the precept because the farmer has invested labor and has a reasonable expectation of future use. Similarly, abandoned property in a public place may be technically unowned, but taking it when others around you have equal claims can still breach the precept if you act with the intention to deprive others.
Traditional commentaries like the Visuddhimagga clarify that the precept applies when "the other person grieves" or would grieve. This introduces an objective standard: if a reasonable person would feel wronged, the precept applies regardless of formal ownership paperwork.
Things held in common—village forests, shared tools, community resources—create special complexity. Taking from such resources without permission or contrary to community norms violates the precept because you're disregarding others' shared claim and the implicit agreement that governs use. This applies even if no single owner exists.
Different Buddhist traditions approach this somewhat differently. Theravada commentaries tend toward strict interpretation: if someone would reasonably expect to control or benefit from something, taking it without consent breaches the precept. Mahayana texts sometimes emphasize compassion and context more heavily, but agree that violation requires some form of harm or deception.
Taking a rock from a mountain stream causes no harm and involves no deception—not a precept violation. Taking wild berries from an unclaimed forest patch is similarly acceptable. But taking vegetables from an abandoned garden plot that someone is clearly still tending, or taking from a lost purse that you could return to its owner, violates the precept because it disregards someone's reasonable interest.
Emergency exceptions exist. If you steal food to prevent someone from starving, the precept is still technically broken, but the harmful consequences are minimized and compassion is operative. Serious practitioners acknowledge this violation honestly rather than pretending it didn't happen, which maintains integrity with the precept as a guide rather than a rigid rule.
A person taking an unowned item with honest uncertainty about its status—genuinely believing it's free to take—acts with less culpability than someone taking it while suspecting others have claims. The precept training involves developing sensitivity to others' interests and honest inquiry before taking. If you're unsure, asking first removes any doubt and aligns your action with the precept's spirit.
Ultimately, the precept against stealing calls for mindfulness about how your actions affect others' wellbeing and their trust in you. Unowned things are genuinely available to take in many cases, but the precept invites you to examine your motivation and consider whether taking causes harm, disappointment, or betrays an implicit understanding in your community.