Ah, an old favorite that's been somewhat phased out in recent play. For 1 turn, all battle damage done to yourself and your monsters is reduced to 0. That means, none of your monsters can be destroyed by battle and you will take no battle damage. It's a simple 1 turn stall in most cases that can be great use when you have something on the field you don't want to lose. Just summoned "Magical Scientist" and he's stuck in attack position? "Waboku" will help ensure that he'll stay around long enough to be switched to defense. It can also be used offensively by activating it on your turn and then attacking a monster with the same ATK as yours. That way your monster will be saved while your opponent's creature would be destroyed.
"Waboku" however will do nothing against effect damage and effects that will destroy your creatures. Also given rise of cards that can prevent traps from being activated (as well as the popular "Jinzo"), more people have been using "Scapegoat" as their alternative (which can also provide limited tribute fodder).
All and all though, "Waboku" is still a solid choice for providing 1 turn of battle protection for all your monsters and yourself just when you may need it the most.
"Waboku" however will do nothing against effect damage and effects that will destroy your creatures. Also given rise of cards that can prevent traps from being activated (as well as the popular "Jinzo"), more people have been using "Scapegoat" as their alternative (which can also provide limited tribute fodder).
All and all though, "Waboku" is still a solid choice for providing 1 turn of battle protection for all your monsters and yourself just when you may need it the most.