The wacky rig is a rig that can be used with all sorts of combinations: weightless, weighted, as well as combined with other rigs like carolina or texas.
In its most basic form, this rig is a hook set through the middle of a worm. Rigged this way the worm will wiggle around violently with your rod movments causing it to attract otherwise lazy bass.
If you add weights to the end of the worm, you can get an even more violent shake out of the worm.
This rig is especially good for fishing near cover, like docks, or logs or stumps where finicky bass might be hiding. The wacky worm wiggle will pull em out amd get em bitin.
#4 to #8 line works great, and when you go to set the hook you only need to give it a little pressure or else that hook will come shootin out of the water at you, especially if it is unweighted. Try the wacky out in shallows, and fish it unweighted if you want it to fall slowly in front of those bass.
Image 2 shows you some examples. Image 3 is a nice wacky catch and image 4 compares this rig to some other popular bass fishing rigs.
Wacky Rig variations - www.vingle.net/posts/396001
Wacky Rigged Drop Shots - www.vingle.net/posts/335654