What was the Ugandan trap?
"The Most Dangerous Game" follows the story of Sanger Rainsford, a man who finds himself stranded on Ship-Trap Island after falling off a yacht en route to a jaguar-hunting trip in Rio de Janeiro. Rainsford encounters a vicious man, General Zaroff, who lives on the island and hunts sailors who have been shipwrecked there as means of entertainment. Rainsford becomes Zaroff's next target and is forced to flee across the island in order to evade Zaroff's murderous plans.
The Ugandan knife trap, thus, refers to the final formal trap that Rainsford sets; Rainsford ties his hunting knife to a young sapling and then uses a wild grapevine to tie back the sapling. This ends up launching the knife into the body of Ivan, Zaroff's assistant, killing the man. Unfortunately, Zaroff is left unharmed.
The Uganda Trap was a trick used by the natives of Uganda. You You find a young sapling that is flexible and can be tied back. You take the knife and tie it to the sapling and make sure the point is facing in the direction of the oncoming enemy, which is this case was Zaroff, Ivan and the dogs. Rainsford was hoping it would get Zaroff, but instead, it killed Ivan.
Rainsford decides that he will capture Zaroff, by setting a trap. If Zaroff "trips" it, a dead tree will fall on top of him. It works only partially, as the Zoroff's shoulder is injured but he is not killed.
Rainsford sets a second trap in a bed of quicksand, called the "Death Swamp." But a dog springs it and this trap fails as well.
The Uganda trap is a native trick Rainsford had learned in
Uganda. In order to make it work he attaches his hunting
knife to a springy young sapling with the blade pointing down the
trail; with a bit of wild grapevine he tied back the sapling.
The recoil of the knife was meant to take out Zaroff, but it took
out Ivan, instead.