If used in succession with other protection moves, it has a 50% chance success rate. Endure runs differently to the other moves. It doesn't prevent damage from attacks, but rather it prevents the Pokémon from fainting.
When Endure is used and is successful, it will prevent the user from being knocked out by leaving the user with 1 Hit Point. This lasts the entire turn so it can receive multiple hits which end up doing no damage. This can be used with multiple strategies and moves including Reversal so that you can get your Hit Points down safely and then do massive damage
Several items and abilities work in a similar manner to Endure; Sturdy leaves the user with 1 Hit Point if the user was to be knocked out when having full Hit Points. In a similar manner, the item Focus Sash works in an identical way. However, the other item; Focus Band will work regardless of Hit Points as it has a 10% chance of allowing the user to hold on from a move which would knock it out. Like the previous item, it'll leave it at 1 Hit Point.