Related Rule
Australia
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
Australia’s Commanders’ Guide (1994) states:
Some weapons and weapons systems are totally prohibited. These blanket prohibitions, which may be traced to treaty or customary international law, are justified on the grounds that the subject weapons are either indiscriminate in their effect or cause unnecessary suffering. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 304.
The Guide adds: “Both chemical and biological weapons are prohibited because they cause unnecessary suffering and may affect the civilian population in an indiscriminate fashion.” 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 306.
Likewise, munitions which produce fragments undetectable by X-ray machines and hollow point weapons are prohibited based upon the principle of unnecessary suffering. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, §§ 308 and 309.
The Guide also provides:
930. It is prohibited to employ weapons, projectiles, materiel and methods of warfare of a nature to cause superfluous injury or unnecessary suffering.
932. Use of the following types of weapons is prohibited:
a. weapons calculated to cause unnecessary suffering. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, §§ 930 and 932(a).
With respect to weapons which are deemed as legal, the Guide states: “All legal weapons are limited in the way in which they may be used. Specifically, no weapons may be used … in such a way as to cause unnecessary suffering.” 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 311.
Australia’s Defence Force Manual (1994) provides:
The principle of unnecessary suffering forbids the use of means and methods of warfare which are calculated to cause suffering which is excessive in the circumstances. It has also been expressed as the infliction of suffering, injury or destruction not actually necessary for the accomplishment of legitimate military objectives. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 207.
The manual adds:
Weapons, projectiles, materials and means of warfare which cause unnecessary suffering are not permissible, that is, when the practical effect is to cause injury or suffering which is out of proportion to the military effectiveness of the weapon, projectile, material or means. Limitations on the use of weapons fall into two broad categories, namely:
a. prohibited weapons, and
b. the illegal use of lawful weapons.
Weapon use will be unlawful under LOAC when it breaches the principle of proportionality by causing unnecessary injury or suffering. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, §§ 401 and 402.
The manual further states:
Some weapons and weapons systems are totally prohibited. These blanket prohibitions, which may be traced to treaty or customary international law are justified on the grounds that the subject weapons are either indiscriminate in their effect or cause unnecessary suffering. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 404.
In this respect, the manual prohibits the use of “weapons calculated or modified to cause unnecessary suffering”. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 405.
Likewise, the manual states: “Both chemical and biological weapons are prohibited because they cause unnecessary suffering and may affect the civilian population in an indiscriminate fashion.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 414.
With respect to weapons which are deemed as legal, the manual states: “All legal weapons are limited in the way in which they may be used. Specifically, no weapons may be used … in such a way as to cause unnecessary injury or suffering.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 415.
With respect to booby-traps, the manual states: “Those that are used must not be designed to cause unnecessary injury or suffering.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 428; see also § 431 (air warfare).
Australia’s LOAC Manual (2006) states:
The principle of avoiding unnecessary suffering forbids the use of means or methods of warfare which are calculated to cause suffering which is excessive in the circumstances. It has also been expressed as averting the infliction of suffering, injury or destruction not actually necessary for the accomplishment of legitimate military objectives. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 2.7
In its chapter on “Weapons”, the manual states:
4.1 Weapons, projectiles, materials and means of warfare which cause unnecessary injury or suffering are not permissible, that is, when the practical effect is to cause injury or suffering which is out of proportion to the military effectiveness of the weapon, projectile, material or means. …
4.2 … Weapon use will be unlawful under the LOAC when it breaches the principle of proportionality by causing unnecessary injury or suffering.
4.4 Some weapons and weapons systems are totally prohibited. These blanket prohibitions, which may be traced to treaty or customary international law, are justified on the grounds that the weapons in question are either indiscriminate in their effect or cause unnecessary suffering.
4.30 … All legal weapons are limited in the way in which they may be used. Specifically, no weapons may be used indiscriminately or in such a way as to cause unnecessary injury or suffering. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, §§ 4.1, 4.2, 4.4 and 4.30.
In the same chapter, the manual states with regard to specific weapons:
4.20 … Both chemical and biological weapons are prohibited because they cause unnecessary suffering and may affect the civilian population in an indiscriminate fashion. …
4.43 Where booby traps are not prohibited, those that are used must not be designed to cause unnecessary injury or suffering. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, §§ 4.20 and 4.43.
In the same chapter, the manual states with regard to rockets, missiles and bombardment:
The LOAC restrictions of proportionality and unnecessary suffering apply to all facets of aerial warfare. With the advent of modern technology many defence forces are now able to deliver weapons with much greater precision. However, nations are not obliged to use only precision munitions; attack by conventional, free-fall weapons or “dumb.” weapons is lawful provided that the overriding the LOAC principles of proportionality and unnecessary suffering and other applicable rules are not violated. 
Australia, The Manual of the Law of Armed Conflict , Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 4.48; see also § 6.26.
In its chapter on “Targeting”, the manual states:
Related to the principle of military necessity, and implicitly contained within it, is the principle of unnecessary suffering. This concept forbids any attack on an enemy, which inflicts unnecessary suffering, injury or destruction. The principles applicable are that:
• the force used must not exceed the minimum required to achieve the military objective;
• there must be a valid military objective;
• destruction as an end in itself is prohibited;
• any destruction of property must contribute to the defeat of the enemy; and
• wanton killing and wilful infliction of suffering, as revenge, are prohibited. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 5.8.
In addition, the manual instructs commanders to take particular care when carrying out offensive support or strike operations, and to take into account various factors, including “prohibitions on the use of weapons, projectiles or other means and methods of warfare that cause superfluous injury or unnecessary suffering”. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 5.52.
In its chapter on “Compliance”, the manual states:
Provisions of the Hague Regulations 1907 are now recognised as part of customary law. Those regulations provide that the following acts are “especially forbidden”:
• to employ arms, projectiles or material calculated to cause unnecessary suffering. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 13.29.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
In 1974, during discussions in the Ad Hoc Committee on Conventional Weapons established by the CDDH, the representative of Australia stated:
41. On the question of weapons that might cause unnecessary suffering, humanitarian principles in weapons design, which Australia wished to see universally accepted, should not be selectively disadvantageous to any country. One factor that should be kept in mind was the differing capacity of countries to maintain high technology or capital-intensive defensive weapons systems, as opposed to manpower-intensive defensive weapons systems at a relatively lower level of technology. It must not be assumed that high-technology sophisticated weapons, if correctly used, were necessarily more inhumane than simpler weapons …
42. His delegation felt that there might have been a tendency in recent studies to place undue emphasis on unnecessary suffering as manifested in wounds of a complex or serious nature, and perhaps in that way to lose sight of the initial and basic St. Petersburg principle that it was better to wound than to kill an enemy combatant. The Committee should consider whether, from the point of view of the soldier involved, it was doing him a service if it fell into the error of giving preference to weapons that tended to kill cleanly, rather than to weapons that wounded, but did not kill. 
Australia, Statement at the CDDH, Official Records, Vol. XVI, CDDH/IV/SR.1, 13 March 1974, pp. 15–16, §§ 41–42.
In a memorandum in 1991, Australia’s Department of Foreign Affairs and Trade stated:
The wide ban on weapons which cause superfluous injury (Article 35(2)) has to be read in conjunction with the Convention on the Prohibition on the Use of Certain Conventional Weapons Which May be Deemed to be Excessively Injurious or to have Indiscriminate Effects. This Convention specifically lists such weapons which are prohibited. Australia became a party to this Convention in 1984. In the light of the Convention a reservation on this ground is unnecessary. 
Australia, Department of Foreign Affairs and Trade, Minute on the Geneva Protocols, File: 1710/10/3/1, 13 February 1991, § 6.
In its oral pleadings before the ICJ in the Nuclear Weapons case in 1995, Australia stated:
One of the most fundamental and longest-standing humanitarian principles is the prohibition on employing weapons or methods of warfare of a nature to cause unnecessary losses or suffering. Yet while this principle has remained constant, its practical application has not and will not. The suffering inflicted by a particular type of weapon may be accepted as “necessary” in one age, but condemned as unnecessary in another. Such changes in the dictates of public conscience may have a number of causes. Advances in technology or changes in methods of warfare may provide alternatives to the use of weapons of that type. Or it may be that in a later age the level of suffering in warfare which the international community is prepared to tolerate is lower than the level which it tolerated previously. 
Australia, Oral pleadings before the ICJ, Nuclear Weapons case, 30 October 1995, Verbatim Record CR 95/22, pp. 39–40.