During the Vietnam War, the Viet Cong were frequently unable to hold their own in stand-up fights against US and allied forces who were superior in strength, firepower, mobility, and logistics.
They relied instead on traditional guerrilla warfare tactics including small-scale hit- and-run attacks, ambushes, terrorist actions, and precision attacks against bases. These included one of the oldest of guerrilla weapons the boobytrap.
This osprey book identifies the various traps used and workings. Although methods like the use of punji stakes pre-dated the Vietnam War, many Vietnamese traps showed the ingenuity of the enemy to be very clever in devising such devices.