Related Rule
Australia
Practice Relating to Rule 96. Hostage-Taking
Australia’s Commanders’ Guide (1994) provides that “taking protected persons as hostages” is a crime likely to warrant institution of criminal proceedings. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 1305(c).
Australia’s Defence Force Manual (1994) provides that hostage-taking is prohibited. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, §§ 953 and 1315.
Australia’s LOAC Manual (2006) states:
The following acts are prohibited at any time and in any place whatsoever:
• the taking of hostages …; and
• threats to commit any of the foregoing acts. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 9.46; see also § 9.58.
In its chapter on “Compliance”, the manual states:
Grave breaches under the Geneva Conventions consist of any of the following acts against persons or property protected under the provisions of the relevant Convention:
• taking hostages. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 13.25.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
Australia’s Geneva Conventions Act (1957), as amended in 2002, provides: “A person who, in Australia or elsewhere, commits a grave breach of any of the [1949 Geneva] Conventions … is guilty of an indictable offence.” 
Australia, Geneva Conventions Act, 1957, as amended in 2002, Section 7(1).
The grave breaches provisions in this Act were removed in 2002 and incorporated into the Criminal Code Act 1995.
Australia’s Criminal Code Act (1995), as amended to 2007, states with respect to war crimes that are grave breaches of the 1949 Geneva Conventions and of the 1977 Additional Protocol I:
268.34 War crime – taking hostages
(1) A person (the perpetrator) commits an offence if:
(a) the perpetrator seizes, detains or otherwise holds hostage one or more persons; and
(b) the perpetrator threatens to kill, injure or continue to detain the person or persons; and
(c) the perpetrator intends to compel the government of a country, an international organisation or a person or group of persons to act or refrain from acting as an explicit or implicit condition for either the safety or the release of the person or persons; and
(d) the person or persons are protected under one or more of the Geneva Conventions or under Protocol I to the Geneva Conventions; and
(e) the perpetrator knows of, or is reckless as to, the factual circumstances that establish that the person or persons are so protected; and
(f) the perpetrator’s conduct takes place in the context of, and is associated with, an international armed conflict.
Penalty: Imprisonment for 17 years.
(2) Strict liability applies to paragraph (1)(d). 
Australia, Criminal Code Act, 1995, as amended to 2007, Chapter 8, § 268.34, p. 325.
The Criminal Code Act also states with respect to war crimes that are serious violations of common Article 3 of the 1949 Geneva Conventions and are committed in the course of a non-international armed conflict:
268.75 War crime – taking hostages
(1) A person (the perpetrator) commits an offence if:
(a) the perpetrator seizes, detains or otherwise holds hostage one or more persons; and
(b) the perpetrator threatens to kill, injure or continue to detain the person or persons; and
(c) the perpetrator intends to compel the government of a country, an international organisation or a person or group of persons to act or refrain from acting as an explicit or implicit condition for either the safety or the release of the person or persons; and
(d) the person or persons are not taking an active part in the hostilities; and
(e) the perpetrator knows of, or is reckless as to, the factual circumstances establishing that the person or persons are not taking an active part in the hostilities; and
(f) the perpetrator’s conduct takes place in the context of, and is associated with, an armed conflict that is not an international armed conflict.
Penalty: Imprisonment for 17 years.
(2) To avoid doubt, a reference in subsection (1) to a person or persons who are not taking an active part in the hostilities includes a reference to:
(a) a person or persons who are hors de combat; or
(b) civilians, medical personnel or religious personnel who are not taking an active part in the hostilities. 
Australia, Criminal Code Act, 1995, as amended to 2007, Chapter 8, § 268.75, p. 352.
Australia’s ICC (Consequential Amendments) Act (2002) incorporates in the Criminal Code the war crimes defined in the 1998 ICC Statute, including “taking hostages” in both international and non-international armed conflicts. 
Australia, ICC (Consequential Amendments) Act, 2002, Schedule 1, § 268.34 and 268.75.