Just out of curiosity I'm looking for examples of laws that require you to do something that puts you in conflict of another law.

This question was sparked by something that happened to my neighbour recently. He found an injured deer in his garden, and trapped it in his shed whilst he tried to find someone to help. A few phone calls later and he found that 1) trapping a wild animal without a license is illegal, and 2) releasing a non-indigenous animal into the wild is also illegal.

So, if he keeps the animal he's breaking the law, and if he releases it he's also breaking the law. I suspect that if he killed and ate it he'd probably also be guilty of 'butchery in an unlicensed premises' or something similar.

Are they any similar examples of mutually exclusive laws?

Update - the deer was a muntjac deer, apparently these are not indigenous (despite being in the UK for over 100 years). According to Wikipedia they are on the list of 'Invasive Alien Species' and cannot be 'intentionally released into the environment'.

I'm not suggesting that there was any realistic likelihood of anyone prosecuting my neighbour, I'm just using this as an example of seemingly mutually exclusive laws.

  • 2
    How is this deer non-indigenous? Presumably it wandered into the yard from a nearby forest.
    – mustaccio
    Aug 23, 2022 at 14:21
  • 3
    Most likely keeping the animal in his shed to make sure it doesn't injure itself isn't "trapping". And most likely putting an animal back to where it came from - in the wild - is not "releasing a non-indigenous animal into the wild".
    – gnasher729
    Aug 23, 2022 at 14:21
  • 1
    Was the deer not indigenous? Either way, undoing the trapping action would likely not meet the definition, (certainly not the intent) of “releasing” since the animal was already part of the local ecosystem vs a new introduction. Interesting hypothetical, I look forward to seeing answers… Aug 23, 2022 at 14:23
  • 1
    Is not 'trapping' an animal specific to setting a trap (e.g. a leg trap), which is not what was done?
    – Jon Custer
    Aug 23, 2022 at 16:37
  • Laws are 'law enforcement tools': law enforcement can use their judgment about whether to charge you or not. if the law wasn't there, they wouldn't have that option. Yes, staffing law enforcement with ethical people, and policing them, IS important. Aug 23, 2022 at 17:08

4 Answers 4


There's a bit of confusion in the question's comments as to whether "trapping" in these circumstances is unlawful:

He found an injured deer in his garden, and trapped it in his shed whilst he tried to find someone to help.

It's not an offence, so there is no Catch 22 - it would be permissible under two seperate pieces of legislation:

First, there's Section 4 of the Animal Welfare Act 2006 which puts the onus on preventing unnecessary suffering to animals:

4 Unnecessary suffering

(1)A person commits an offence if—

  • (a)an act of his, or a failure of his to act, causes an animal to suffer,

  • (b)he knew, or ought reasonably to have known, that the act, or failure to act, would have that effect or be likely to do so,

  • (c)the animal is a protected animal, and

  • (d)the suffering is unnecessary.

Section 2 of the 2006 Act defines "protected animal” to include:

(b)it is under the control of man whether on a permanent or temporary basis

And secondly, on the basis that the shed is considered a "trap" then the defence to an allegation of unlawful trapping contrary to Section 4 Deer Act 1991:

(1)Subject to sections 6 and 8 below, if any person—


  • (b)uses for the purpose of taking or killing any deer any trap ...

he shall be guilty of an offence

Would be at Section 6 of the 1991 Act:


(3)A person shall not be guilty of an offence under section 4(1)(a) or section 4(1)(b) above by reason of setting in position, or using, any trap or net for the purpose of preventing the suffering of an injured or diseased deer.

As the OP rightly points out, releasing a Muntjac deer is an offence under Section 14, Wildlife and Countryside Act 1981

...any person releases or allows to escape into the wild any animal which—

  • (a)is of a kind which is not ordinarily resident in and is not a regular visitor to Great Britain in a wild state; or

  • (b)is included in Part I, IA or IB of Schedule 9,

he shall be guilty of an offence.

Schedule 9 of the 1981 Act includes:

Common Name: Deer, muntjac

Scientific Name: Muntiacus reevesi


The principle of implied repeal generally ensures that mutually incompatible laws cannot exist.

For example, let's say the hypothetical Red Hats Act 1990 makes it a criminal offence to wear a red hat at any time. Later, Parliament passes the Christmas Party Act 2000 and makes it a legal requirement to wear a red santa hat on Christmas day.

What should you do to comply with the law? You should wear a red had on Christmas day. The later Act impliedly repeals the earlier Act to the extent of the contradiction. The previous provision that it is illegal to wear a red hat at any time is now (impliedly) a provision that it is illegal to wear a red hat at any time other than on Christmas day.


In your example, obedience to the law is not impossible, as suggested. The breaking of the law arose w.r.t. only one law: trapping (and actually that law was not broken, but I'm only addressing the premise that there is a contradiction inherent in the two laws). It is possible to obey both laws, and that is what you are supposed to do.

The courts will interpret two laws that seem to be contradictory in a fashion that is non-contradictory. Seeming contradictions might arise in the US because there are local, state and federal laws, but these are hierarchical jurisdictions, so that local law applies only when state law does not say otherwise, and state law only applies when federal law doesn't say otherwise.


There are other situations.

Download GPL v.3 licensed source code. Pay for a closed source license to proprietary source code. Combine both to a computer program.

Sell the computer program or give it to someone.

Now you have two choices: You need to hand over the complete source code (GPL licensed plus proprietary) or you commit copyright infringement due to the GPL license. And you need to NOT hand over the proprietary code, otherwise it is again copyright infringement and breach of contract. Whatever you do, you're in the wrong.

(Third choice: Destroy all the copies you handed out. Probably breaks even more laws).

Obviously this is self inflicted. Somewhere in comments to the GPL license I read "If you can't conform to the GPL license without being in breach of some contract or breaking a law, then don't use GPL licensed code".

(Or imagine a country where you are not allowed to distribute source code to security critical software. In that case, don't use GPL licensed code in your software).

  • Yes. Two options, and both illegal. I must admit, proving that his example is actually twice legal was fascinating.
    – gnasher729
    Aug 23, 2022 at 16:20
  • I'm downvoting because this is not an example of situation where you are forced to choose between breaking two laws but rather, between breaking two contracts / licences. The latter is far less interesting because it is trivially easy for anyone at any time to agree two contracts where it is impossible to comply with both. Finding two such laws however is much more difficult (and is what the question is asking for).
    – JBentley
    Aug 24, 2022 at 14:39
  • Also, the courts generally do not care that you have mutually incompatible contractual obligations and will resolve that via the usual remedies (damages, specific performance) etc.) thus putting all parties under both contracts in a fair position (from a legal perspective). On the other hand, the courts are never going to enforce two incompatible laws and will instead interpret those laws and rule on which one is applicable.
    – JBentley
    Aug 24, 2022 at 14:57

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