Page "Pang Tong" Paragraph 4

When Liu Bei led his army to Yi Province ( covering the Sichuan Basin ) to help Liu Zhang defend against Zhang Lu's invasion, Pang suggested to Liu Bei to take Liu Zhang hostage when they meet and force Liu to hand over Yi Province.

Liu Bei declined and allowed Liu Zhang to return to Chengdu ( capital city of Yi Province ), on the grounds that he did not want to take the risk and that he was still unfamiliar in the area.

When relations between Liu Bei and Liu Zhang deteriorated until the point of war, Pang Tong offered three options for his lord to take, namely the upper, middle and lower plans.

The upper plan involved sending an elite special task force to invade Chengdu secretly, take Liu Zhang by surprise and force him to surrender.

The middle plan was to spread false information that Liu Bei was returning to Jing Province, then lure Liu Zhang's generals Yang Huai and Gao Pei away from their positions, kill them and take over their castles and armies, and finally advance towards Chengdu.

The lower plan entailed retreating to Jing Province and await for another time to attack Yi Province.

Liu Bei chose the middle one and requested reinforcements from Liu Zhang to deal with Zhang Lu.

Liu Zhang sent him only a small number of troops with low fighting capability and a mediocre amount of supplies.

Liu Bei rallied his troops to turn against Liu Zhang and killed Yang Huai and Gao Pei, on charges of showing disrespect towards him, and took over command of their armies.

Liu Bei's forces then attacked Liu Zhang's city of Luo, which was defended by Liu Zhang himself, and besieged the city for over a year.