The offence of intentionally causing injury is created by Crimes Act 1958 s18.
The offence has the following four elements:
The complainant suffered an "injury";
The accused caused the complainant’s injury;
The accused intended to cause injury; and
The accused acted without lawful justification or excuse.
Although s18 also proscribes recklessly causing injury, it is a separate offence (R v His Honour Judge Hassett and Anor (1994) 76 A Crim R 19). See Recklessly Causing Injury for information concerning that offence.
The Crimes Amendment (Gross Violence Offences) Act 2013 substituted a new definition for “injury”, which had previously been defined inclusively. Due to the operation of the transitional provision, Crimes Act 1958 s618, the new definition only applies to offences committed on or after the commencement of the amending Act, 1 July 2013.
Where an offence is alleged to have been committed between two dates, one date before and one date after 1 July 2013, the law in force prior to the amendments applies (Crimes Act 1958 s618).
This topic separately describes the operation of this element for offences committed before and after 1 July 2013.
Injury after 1 July 2013
From 1 July 2013, Crimes Act 1958 section 15 contains the following relevant definitions:
a) Physical injury; or
b) Harm to mental health;
whether temporary or permanent
Harm to mental health includes psychological harm but does not include an emotional reaction such as distress, grief, fear or anger unless it results in psychological harm;
Physical injury includes unconsciousness, disfigurement, substantial pain, infection with a disease and an impairment of bodily function.
Injury before 1 July 2013
For offences committed before 1 July 2013, “injury” is an ordinary English term. It is for the jury to determine, as a question of fact, whether the complainant suffered an injury (R v Welsh & Flynn Vic CCA 16/10/1987; R v Ferrari  VSCA 186).
The jury may compare the injury in question with harm which common experience suggests would be superficial or trifling, and therefore fall short of being an “injury” (R v Welsh & Flynn Vic CCA 16/10/1987; R v Ferrari  VSCA 186; R v Cogley  VR 799).
The jury is not restricted to considering physical injuries. “Injury” includes unconsciousness, hysteria, pain and any substantial impairment of bodily function (Crimes Act 1958 s15).
The definition of “injury” as in force before 1 July 2013 is not exhaustive. Jurors are free to use their own experiences when determining whether or not the complainant has suffered an injury (R v Welsh & Flynn Vic CCA 16/10/1987; R v Ferrari  VSCA 186).
For offences committed on or after 1 July 2013, the Crimes Amendment (Gross Violence Offences) Act 2013 expanded the meaning of the word “injury”. Harm to mental health, disfigurement and infection with a disease were not expressly mentioned in the definition of “injury”. Decisions from other jurisdictions that harm to mental health and infection with a disease could constitute “grievous bodily harm” may provide guidance on whether those harms can constitute “injury” (see R v Ireland  AC 147; R v Dica  QB 1257; R v Aubrey (2012) 82 NSWLR 748).
The complainant’s injury must have been caused by the accused. For detailed information about causation, see Causation.
The injury does not need to have been caused by the accused personally assaulting the complainant. This element will be satisfied even if s/he caused the injury indirectly (R v Salisbury  VR 452).
It is not sufficient that the accused intended to do the act that injured the complainant. S/he must have intended to inflict injury (see R v Westaway (1991) 52 A Crim R 336).
The nature of the accused’s acts may provide evidence of his/her intention (R v McKnoulty (1995) 77 A Crim R 333).
The accused does not need to have intended the precise injury s/he ultimately caused. It is only necessary that the accused intended to cause an injury and actually causes an injury (Royall v R (1991) 172 CLR 378; R v Demirian  VR 97).
Intention and causation must always be treated as separate issues. This is especially important if the accused did not directly cause the complainant’s injury. In such cases, the jury must separately assess whether the accused caused the injury, and whether s/he intended to cause the injury (R v McKnoulty (1995) 77 A Crim R 333; Royall v R (1991) 172 CLR 378).
The accused’s capacity to form the relevant intention may have been affected by drugs and alcohol (R v Mala Vic CA 27/11/1997; R v Kumar (2006) 165 A Crim R 48; R v Faure  2 VR 537). See Common Law Intoxication for further information on this point.
Without Lawful Excuse
The prosecution must disprove any defences which are open on the evidence (R v Roach  VR 665).