Ruses de guerre are described from ancient to modern times, both in semi-mythical accounts such as the story of the Trojan Horse in Virgil's Aeneid, and in well-documented events such as the flying of the American flag by the British ocean liner RMS Lusitania in 1915 (whilst the United States was a neutral country) to deter attack by German submarines; they also feature in fiction.
Good faith is required, but at least 17 different types of ruse, including ambushes, false radio messages, the use of spies and the use of dummy guns, are considered legitimate as long as they do not involve treachery or perfidy.
[2] Alexander the Great walked his men up and down a river continuously to condition his opponent, Porus, into a false sense of security in the belief that his whole army was searching for a ford.
As stated in the probably fictional account in Romance of the Three Kingdoms, Zhuge Liang tricked Sima Yi using the Empty Fort Strategy from Sun Tzu's The Art of War.
Zhuge Liang sat upon the walls and played his instrument, seemingly calm and composed, tricking Sima Yi into thinking that the Shu troops had hidden in the surrounding area for an ambush.
The Siege of Detroit was an early engagement in the War of 1812, where a smaller British-First Nations force, led by Major-General Isaac Brock and Shawnee leader Tecumseh, used bluff and deception to intimidate Brigadier General William Hull into surrendering the fort, the town of Detroit, and a dispirited American force that nevertheless outnumbered the British and First Nations.
It is far from my intention to join in a war of extermination, but you must be aware, that the numerous body of Indians who have attached themselves to my troops, will be beyond my control the moment the contest commences.To further the illusion that a large First Nations force was attached with Brock's force, Tecumseh extended his men, and marched them three times through an opening in the woods at the rear of the fort in full view of the fort.
During First and Second World Wars, Q-ships were heavily armed merchant ships with concealed weaponry, designed to lure submarines into making surface attacks.
Skorzeny was acquitted by a United States military court in Dachau in 1947, after his defense counsel argued that the "wearing of American uniforms was a legitimate ruse of war for espionage and sabotage" as described by The New York Times.
[11][12] Article 23 of the 1907 Hague Convention IV – The Laws and Customs of War on Land provides that: "It is especially forbidden....(b) To kill or wound treacherously individuals belonging to the hostile nation or army....(f) To make improper use of a flag of truce, of the national flag, or of the military insignia and military uniform of the enemy, as well as the distinctive badges of the Geneva Convention".
In general, it would be an improper practice to secure an advantage over the enemy by deliberate lying or misleading conduct which involves a breach of faith, or when there is a moral obligation to speak the truth.