united-kingdom property ownership
Does my neighbour have to return my football?
<p>I kicked a football into my neighbour's back garden.</p>

<p>Is my neighbour legally obliged to return it? If not, what restrictions govern his use of the football?</p>

<p>In kicking the football onto his property, you might be liable for negligent trespass, but that would be for a court to decide, and any court-ordered remedy would be related to the harm that you did him by your negligence. Fortunately you did not compound the wrong by trespassing to retrieve your property. The football being your property, it is not his, and he has no right to keep it. In keeping it, he has committed the intentional tort of conversion, by refusing to surrender your property to you (I assume you asked). Negligent trespass is not a crime anywhere, as far as I know, but intentional conversion is.</p>

<p>The cost of litigating a civil suit is prohibitive, but it would probably fall under the definition of a lower (misdemeanor) level of theft in your state, which the government may pursue at their option. For instance, in Washington, RCW 9a.56.020, theft means:</p>

<blockquote>
  <p>(a) To wrongfully obtain or exert unauthorized control over the
  property or services of another or the value thereof, with intent to
  deprive him or her of such property or services; or</p>
  
  <p>(b) By color or aid of deception to obtain control over the property
  or services of another or the value thereof, with intent to deprive
  him or her of such property or services; or</p>
  
  <p>(c) To appropriate lost or misdelivered property or services of
  another, or the value thereof, with intent to deprive him or her of
  such property or services.</p>
</blockquote>
