While the offence of theft is created by Crimes Act 1958 s74, its basic definition is set out in s72(1), with further explanation provided by s73.
The offence has the following three elements which the prosecution must prove beyond reasonable doubt:
The accused appropriated property belonging to another;
The accused did so with the intention of permanently depriving the other of the property; and
The accused acted dishonestly (Crimes Act 1958 s72).
The law of theft draws heavily upon the civil law of property. This commentary does not attempt to offer a detailed discussion of that law.
Appropriation of property belonging to another
For the first element to be met, the jury must be satisfied that:
The accused appropriated something;
The thing appropriated was property; and
The property belonged to another person.
Theft can only be committed by an act of "appropriation" (Crimes Act 1958 s72(1)).
The accused will have "appropriated" property if s/he:
Assumed any of the rights of the owner (Crimes Act 1958 s73(4)); and
Adversely interfered with or usurped the owner’s rights in some way (Roffel v R  VR 511).
Assumption of the owner’s rights
A person "assumes the rights" of an owner by taking on the right to do something which the owner has the right to do by virtue of his or her ownership (Stein v Henshall  VR 612).
There is no simple categorisation of the rights which constitute "the rights of the owner". This must be determined by reference to the civil law of property (Roffel v R  VR 511; Stein v Henshall  VR 612; W (a child) v Woodrow  VR 358).
The rights of the owner generally include the right to control the property and the right to possess it (see, e.g., Roffel v R  VR 511; Stein v Henshall  VR 612; W (a child) v Woodrow  VR 358).
This requirement will be satisfied if the accused has taken on any of the owner’s rights. The prosecution does not need to prove the accused assumed all of those rights (Stein v Henshall  VR 612; W (a child) v Woodrow  VR 358).
Depending on the circumstances, "appropriation" can involve taking, using, damaging, extinguishing, lending, retaining or offering to sell another person’s property (or any of their property rights) (see, e.g., R v Williams (2001) 1 Cr App R 23; Roffel v R  VR 511; Stein v Henshall  VR 612; W (a child) v Woodrow  VR 358).
Adverse interference with the owner’s rights
To have "appropriated" property, the accused must have adversely interfered with or usurped the owner’s rights in some way (R v Morris  AC 320; Roffel v R  VR 511). 
The accused will therefore not have appropriated property if s/he acted with the owner’s consent (R v Morris  AC 320; Roffel v R  VR 511).
The owner’s consent will only prevent an act from being considered an "appropriation" if that consent was real. If the consent was induced by fraud, deception or false representation, the accused will be regarded as having appropriated the property, despite the owner’s purported consent (Lawrence v Metropolitan Police Commissioner  AC 626; R v Baruday  VR 685; R v Gomez  VR 685).
Innocent acquisition of property
If the accused came by the property innocently, but later assumed a right to it by keeping or dealing with it as an owner, s/he will have appropriated it (Crimes Act 1958 s73(4)).
However, if s/he purchased the property (or any "right or interest" in property) in good faith for value, but received a defective title, his/her assumption of the owner’s rights are deemed not to be theft (Crimes Act 1958 s73(5)).
The thing that the accused appropriated must have been "property" (Crimes Act 1958 s72(1)).
"Property" is defined to include "money and all other property real or personal including things in action and other intangible property" (Crimes Act 1958 s71(1)).
This definition includes some things with no physical existence, such as debts (R v Baruday  VR 685; R v Holt (1983) 12 A Crim R 1, 16-17).
However, other intangible items may not be classified as property. For example, in England it has been held that confidential information is not property (Oxford v Moss (1978) 68 Cr App R 183), and copyright may not be (R v Lloyd  1 QB 829).
While electricity is not property under this definition (Low v Blease  Crim L R 513), fraudulent abstraction, wastage, use, diversion or consumption of electricity is punishable as theft through the combined effect of State Electricity Commission Act 1958 s 107 and Electric Light and Power Act 1958 s 51 (repealed).
Whether the thing assumed by the accused was "property" can involve questions of both law and fact. It is for the judge to determine as a question of law whether a particular circumstance creates a property right, but if in issue, it will be for the jury to determine whether that circumstance existed as a question of fact (See R v Hall  QB 126).
Special forms of property
Land and things forming part of land can only be stolen in the limited circumstances specified in Crimes Act 1958 s73(6).
Section 73(6) provides that a person may commit theft of land or fixtures where:
the accused is a trustee, personal representative or authorised by power of attorney or as a liquidator of a company to sell or dispose of land belonging to another and deals with it in breach of the confidence reposed in him or her;
where the accused severs something from the land; or
where a tenant appropriates a fixture or structure let to be used with the land.
Section 73(6)(a) specifically recognises that a person may be a personal representative but not a trustee. The section also allows land to be stolen even if the accused is both the legal and beneficial owner of the land, where there is a dealing with it in breach of confidence (Coleman v DPP  VSCA 264, , ).
Wild animals are regarded as property, but may only be stolen in the circumstances specified in Crimes Act 1958 s73(7). 
Property must be in existence
Property must be in existence before it can be appropriated (Akbulut v Grimshaw  3 VR 756).
Accordingly, creating a future obligation in the owner of a telephone service to pay for unauthorised telephone calls does not involve theft of property (Akbulut v Grimshaw  3 VR 756).
Belonging to another
It is only theft if a person appropriates property "belonging to another" (s72(1)).
Property "belongs" to anyone who has possession or control of it, or who has any other proprietary right or interest in it (Crimes Act 1958 s71(2)).
These interests include legal and equitable proprietary interests (R v Clowes (No 2)  2 All ER 316).
However, property does not "belong" to a person who only has an equitable interest in that property, if that equitable interest arose from an agreement to transfer the property or grant an interest in it (Crimes Act 1958 s71(2)).
Whether a person has a proprietary right or interest is a question of civil property law (R v Walker  Crim LR 112).
The prosecution needs only to establish that someone other than the accused had property rights that were appropriated. There is no requirement that the prosecution prove who actually held those rights (Lodge v Lawton  VR 112).
It does not matter if the accused has property rights in the relevant property. If someone else also has property rights in it (e.g., a partner), the property "belongs to another" and can be appropriated (R v Bonner  WLR 838).
Property no longer "belongs" to a person who has intentionally relinquished all ownership rights (abandoned the property) (R v Small  Crim LR 777).
However, there is a distinction between "losing" and "abandoning" property. Property which is merely lost still "belongs" to the owner and can be appropriated (R v Small  Crim LR 777).
Ownership in special cases
Section 73 of the Crimes Act 1958 describes four special cases where property is deemed to "belong to" people who might not otherwise be regarded as property owners. These cases are where the property is:
Subject to a trust (s 73(8));
Held under a fiduciary obligation (s 73(9));
Subject to an obligation to make restoration (s 73(10)); or
The property of a corporation sole (s 73(11)).
Property subject to a trust (s73(8))
Although trust property will ordinarily "belong to" the beneficiaries of the trust (due to the application of Crimes Act 1958 s71(2)), in some cases there will not be any beneficiaries (e.g., a purpose trust).
In such cases, the property subject to the trust is deemed to belong to anybody having a right to enforce the trust (Crimes Act 1958 s73(8)).
Property held under a fiduciary obligation (s73(9))
Section 73(9) covers the situation where a person, who is not a trustee, appropriates property (or proceeds from property) while under a fiduciary obligation to use the property in a particular way. In such a case, the property is deemed (as against the fiduciary) to belong to the beneficiary of the obligation.
The "obligation" must be a "legal obligation" (R v Meech  QB 549; R v Arnold  4 All ER 1).
This provision applies only where the accused was required to deal with the particular property (or its proceeds) in a particular way. A mere contractual obligation to provide a service in return for payment is not sufficient (R v Hall  QB 126).
Accordingly, this provision was held not to apply where a travel agent received payments for air tickets, but did not provide the tickets or return the money. It was held that the accused had only entered a contractual obligation to provide the air tickets, and was not required to use the customer’s particular deposit for obtaining those tickets (R v Hall  QB 126).
Property subject to an obligation to make restoration (s73(10))
Crimes Act 1958 s73(10) addresses the situation where:
A person (the "receiver") received property by the mistake of another;
The receiver was not aware at the time that a mistake was being made, or had not yet decided to dishonestly retain the property; 
The mistake was not "fundamental" (i.e. it did not concern the identity of the receiver, or the nature or volume of the property);  and
The receiver is under an obligation to return the property.
Section 73(10) provides that in such circumstances, the property is to be regarded (as against the receiver) to belong to the person entitled to restoration. A dishonest decision not to return the property can therefore amount to theft (see, e.g., Attorney-General’s Reference (No 1 of 1983)  QB 182).
The obligation to restore the property must be a "legal obligation" (R v Gilks  1 WLR 1341).
Whether there is a legal obligation to restore is a question of civil property law (Chase Manhattan Bank NA v Israel-British Bank (London) Ltd  Ch 105).
Property of a corporation sole (s73(11))
The property of a corporation sole is regarded as belonging to the corporation, notwithstanding any vacancy in the corporation (Crimes Act 1958 s73(11)).
This provision covers the situation where property is stolen from a corporation sole, and the incumbent is dead or the position is otherwise vacant.
Intention to permanently deprive
The second element of theft requires the accused to have intended to permanently deprive the owner of the property when s/he appropriated it (Crimes Act 1958 s72(1)).
If the accused only had an intention to temporarily deprive the owner of his or her property, this element will not be met (subject to the exceptions specified in s73 (see below)) (R v Lloyd  1 QB 829).
Similarly, this element will not be met if the accused had not decided how s/he was going to dispose of the property when s/he appropriated it (subject to the exceptions specified in s73 (see below)). She must have already formed the intention to permanently deprive the owner of the property at the time of the appropriation (R v Easom  2 QB 315; Sharp v McCormick  VR 869).
Where the period or circumstances of the appropriation are such that the accused intends to return the property only after the owner’s interest has been fundamentally changed (e.g. returning a concert ticket after the performance), this may amount to an intention to permanently deprive the owner of that property (R v Lloyd  1 QB 829).
A person who takes property (e.g., goods or cash), intending to return equivalent (but not identical) property, will have an intention to permanently deprive the owner of the property (because s/he does not intend to return the exact same coins, notes or goods that s/he took) (R v Williams  1 QB 660; R v Cockburn  1 All ER 466; R v Pace  3 Can CC 55 (NSSC)).
Acting regardless of the owner’s rights: s73(12)
The accused is deemed to have an intention to permanently deprive a person of property, despite the fact that s/he did not actually have that intention when s/he appropriated the property, if s/he intends to treat the property as his or her own to dispose of regardless of the owner’s rights (Crimes Act 1958 s73(12)).
Section 73(12) will only be relevant in exceptional cases. It is apt to confuse and should only rarely be introduced into a charge (R v Dardovska (2003) 6 VR 628).
Circumstances in which s73(12) has been held to be relevant include:
Where the accused takes the property, promising to return it only in exchange for payment (R v Lloyd  1 QB 829);
Where the accused takes the property, intending to return it only after fundamentally altering its nature (e.g., returning the piece of paper a cheque is written on, after receiving payment from the bank) (R v Duru  1 WLR 2);
Where the accused takes the property, while leaving open the possibility that s/he might return it to the owner at a later date, but in the meantime treats it as his/her own (Sharp v McCormick  VR 869).
Two other circumstances in which s73(12) may be relevant are:
Where the accused borrows the property from its owner, ultimately intending to return it; or
Where the accused lends the owner’s property to a third party, intending to return it to the owner upon retrieving it.
In such cases, the accused will only be deemed to have an intention to permanently deprive the owner of the property if the borrowing or lending was for a period, or in circumstances, which made it equivalent to an outright taking or disposal (Crimes Act 1958 s73(12)).
Section 73(12) may also be relevant where the accused parts with property belonging to another, under a condition as to its return which s/he may not be able to perform (e.g., pawning it). If this was done for the accused’s own purposes, and without the consent of the owner, the accused will be deemed to have treated the property as his or her own to dispose of regardless of the owner’s rights (Crimes Act 1958 s73(13)). By virtue of s73(12), s/he will be regarded as having had an intention to permanently deprive the owner of that property.
Motor vehicles and aircraft
Proof that a person used, in any manner, a motor vehicle or aircraft without the consent of the owner or lawful possessor is conclusive evidence that the person intended to permanently deprive the owner of that property (Crimes Act 1958 s73(14)).
Section 73(14) applies if the vehicle is used "in any manner". This can include situations where there is no movement or attempted movement of the vehicle (Inglis v Davies  VR 438).
The provision can also apply to a person who rides as a passenger in a vehicle he or she knows to be stolen (W (a child) v Woodrow  VR 358).
Intention to deprive special owners
A person who intends to defeat a trust is regarded as having an intention to deprive any person having a right to enforce the trust of the trust property (Crimes Act 1958 s73(8)).
Where a person receives property by mistake, and is under an obligation to restore that property, an intention not to do so is regarded as an intention to deprive the person of the property (or its proceeds) (Crimes Act 1958 s73(10)).
The accused’s appropriation of property belonging to another will only be theft if it is "dishonest" (Crimes Act 1958 s72(1)).
Dishonesty has a special meaning when used in Division 2 of the Crimes Act 1958. It means that the accused acted without any claim of legal right (R v Salvo  VR 401; R v Bonollo  VR 633 and R v Brow  VR 783).
This interpretation of "dishonesty" differs from the interpretation of "dishonesty" in the equivalent provision of the English Theft Act and the interpretation of "dishonesty" in s86 of the Commonwealth Crimes Act 1914. In those jurisdictions, "dishonesty" has its ordinary meaning, and is assessed according to the standards of the ordinary person (Peters v the Queen (1998) 192 CLR 493; Macleod v the Queen (2003) 214 CLR 230; R v Ghosh  QB 1053). 
In Victoria, section 73(2) restates this general definition in the context of theft, and adds two deeming provisions. It provides that a person’s appropriation is not to be regarded as dishonest if the person believed that:
S/he had a legal right to deprive the owner of the property; or
The owner would have consented to the appropriation if s/he had known of it and the circumstances surrounding it; or
The owner could not be discovered by taking reasonable steps.
The term "dishonestly" in s72(1) has no residual meaning beyond this statutory definition (R v Salvo  VR 401; see also R v Bonollo  VR 633 and R v Brow  VR 783).
Belief in a legal right to deprive: s73(2)(a)
The accused’s appropriation of property will not have been dishonest if s/he believed that s/he had a legal right to deprive the other person of the property (s73(2)(a)).
The belief must relate to a right "in law" – a claim of legal right. A claim of moral right is not sufficient (Crimes Act 1958 s73(2)(a)).
The claim of right must extend to all of the property taken, not just to part of it (R v Bedford (2007) 98 SASR 514).
It does not matter if the accused’s belief was based on a mistake of fact  or a mistake of law.  If the accused genuinely believed s/he had a legal claim of right, s/he will not have acted dishonestly (R v Langham (1984) 36 SASR 48; R v Lopatta (1983) 35 SASR 101).
The accused merely needs to have believed s/he had a legal right to the property. S/he does not need to have believed that s/he had the right to use the measures s/he used to take the property (R v Bedford (2007) 98 SASR 514; R v Salvo  VR 401).
So even if the accused used violent measures to take the property, s/he should not be convicted of theft if s/he genuinely believed s/he had a right to the property. However, s/he may be convicted of an offence relating to the violence used (R v Bedford (2007) 98 SASR 514; R v Salvo  VR 401).
Belief that the owner cannot be discovered: s73(2)(c)
A person will not have acted dishonestly if s/he appropriated the property in the belief that the person to whom the property belongs could not be discovered by taking reasonable steps (Crimes Act 1958 s73(2)(c)).
This provision covers the case of a person who finds property, or who receives property by mistake. As long as the finder or receiver genuinely believed that the owner could not be identified or located by taking reasonable steps, they will not be guilty of theft (R v MacDonald (1983) 8 A Crim R 248).
This provision does not apply where the accused gained the property as a trustee or personal representative (Crimes Act 1958 s73(2)(c)).
The nature of the accused’s beliefs
Dishonesty is a subjective concept. The jury is concerned with the accused’s subjective beliefs (R v Salvo  VR 401 per Murphy J).
Each form of "honesty" outlined in s73(2) relies upon the accused having held a particular belief. That belief:
Must have been honestly or genuinely held (R v Salvo  VR 401; R v Bernhard (1984) SASR 48); and
Does not need to have been reasonable. The jury can, however, take into account the reasonableness of the belief in assessing if it was genuinely held (R v Salvo  VR 401; R v Dardovska (2003) 6 VR 628).
Willingness to pay for the property: s73(3)
The accused’s appropriation of property belonging to another may have been dishonest, even though s/he was willing to pay for the property (Crimes Act 1958 s73(3)).
This does not mean that the accused’s willingness to pay can never prove that she was not acting dishonestly. It simply means that the fact that s/he was willing to pay does not necessarily exclude dishonesty (R v Senese  VSCA 136).
Need for concurrency of elements
The prosecution must prove that each of the three elements of theft existed at the same time (R v Greenberg  Crim LR 331).
In cases where the accused appropriates property which s/he was under a fiduciary obligation to use in a particular way, it is sufficient that the person acted dishonestly at the point of appropriation. There is no need for the receipt of the property and the dishonest appropriation to coincide (R v Hall  QB 126).
 The proposition that appropriation must involve an adverse interference with the owner’s rights was rejected by the House of Lords in R v Gomez  AC 442 and R v Hicks  4 All ER 833, and was also criticised (in obiter) by McHugh and Callinan JJ in MacLeod v The Queen (2003) 214 CLR 230. However, Roffel v R  VR 511 remains the leading authority on the issue in Victoria.
 These include where the animal is tamed and kept in captivity; where the animal has been reduced into possession and has not been lost or abandoned; or where a person is in the course of reducing the animal into possession.
 If the receiver was aware that a mistake was being made, and dishonestly decided to accept the property anyway, s73(10) will not be necessary – as the property will still have "belonged" to the person making the mistake at the time of the appropriation.
 If the mistake was fundamental, then the original owner will retain property rights in the relevant property, and so s73(10) will not be necessary.
 Other Australian jurisdictions adopt different approaches to dishonesty, and their authorities should be approached with caution.
 A mistaken belief that certain facts existed, which would have created a legal claim if true.
 A mistaken belief that certain interests create legal rights.