Cette tactique, Frédéric II l’employa lors de la bataille de Leuthen en 1757. Cette tactique permettait de pallier au carences de «l’ordre mince». En effet, au XVIIIème siècle, les armées sont disposées sur 3 ou 4 rangs afin d’exploiter au mieux la puissance de feu des armements modernes. Il s’en suit un étirement des forces qui empêche toute offensive d’envergure. L’ordre oblique permettait donc de bénéficier des avantages de la puissance de feu tout en créant les conditions propices à une engagement massif et de rupture
The oblique order (or declined or refused flank) is a military tactic where an attacking army focuses its forces to attack a single enemy flank. The force commander concentrates the majority of his strength on one flank and uses the remainder to fix the enemy line. This allowed a commander with weaker or equal forces to achieve a local superiority in numbers. The commander can then try to defeat the enemy in detail. It was the most famously used by the armies of Frederick II of Prussia. Oblique order required disciplined troops able to execute complex maneuvers in varied circumstances.
In the oblique order attack, commander of the army would intentionally weaken one portion of the line to concentrate their troops elsewhere. They would then create an angled or oblique formation, refuse the weakened flank and attack the strongest flank of the enemy with a concentration of force. Once the critical flank was secure, the commander would wheel their troops 90 degrees to roll up the enemy line and the angled formation would continue to advance. On occasion both commanders would attempt the same tactic (e.g.the Diadochi trying to replicate Alexander's tactics).