Ladder ball is a leisure game, so rules aren't hard and fast. Here, we'll go by the most common instructions, particularly those developed by Ladder Golf, Inc., but you'll find lots of variations out there.
Right out of the box, you've got either one or two ladders, about 3 feet tall and 2 feet wide (1 meter by 0.5 meter), and six bolas in two different colors. Each bola is a roughly a foot-long (0.3 meter) vinyl cord with a golf ball on each end. Game play is basically the same whether you're using one ladder or two; all that really changes is where the players stand.
To set the game up, place the ladder(s) on the lawn and establish a "toss line." If you're using two ladders, they can serve as each other's toss lines. The active player has to stay behind this line, which is typically about five paces, or 15 feet (4.5 meters) to be exact, from the ladder, though some instructions have the distance as high as 25 feet (7.5 meters) [source: Ladder Golf, Amazon]. Bola colors vary by brand, but let's say they're red and blue. One player gets all three red bolas, and the other all three blue ones.
Next, flip a coin for first-up. From behind the toss line, the first player – let's say the red one – tosses each red bola at the ladder. It's allowed to bounce off the ground first. The point is to wrap each one around a rung.
(Variation: Bolas that bounce don't count.)
After Red tosses all three, Blue is up. Six tosses make up a round of game play.
(Variation: Red tosses one, then blue tosses one, and so on until all six are thrown.)
You can toss any way you want, though underhand is standard. It's a good idea to keep the balls separate as you toss so they hit the ladder spread out, ready to hang. An effective method is to hold one ball in your hand while the other dangles, and then gently arc the bola toward the ladder rung you're going for.
When I played, I just aimed in the general direction of the ladder and hoped something stuck. But if you're playing to win, you may need to hit a specific rung, because you want a specific number of points. This is probably the most complicated aspect of the game.