This paper studies the performance of modern guided systems in presence of a proposed deception jamming technique. The proposed jammer uses the intercepted signal of the guided system to deceive the instantaneous amplitude comparison (IAC) monopulse radar, which is used in the most modern guided system. The performance of the modern guided systems in the presence of jamming for a typical case of radar guided missile is discussed for the following guidance methods: proportional navigation, pure pursuit, and constant bearing. It is found that, the guided system that uses pure pursuit guidance method is the most affected by the proposed jamming technique (largest miss tracking distance). Constant bearing guidance method is the lowest method affected by the proposed jamming technique (lowest miss tracking distance). Proportional navigation, that is the most used guidance method, is moderate affected by the proposed jamming technique. This effect is enough to confuse the guided system and miss track the target.