During one story (the "old cow" story), the GM plants a story event that looks like a plot hook, but has vague or totally undefined consequents. This is the "magic beans." Next, when the GM wants to draw the PCs into another story (the "cloud giant" story), he creates a follow-up event in which the consequents of the magic beans are revealed (the "beanstalk"). The name of the technique and its elements derive from the classic story of Jack and the Beanstalk.
Jack is a young boy. His ailing, widowed mother is poor. Their cow stops giving milk, so she sends Jack to market to sell the cow. On the way to the market, an old man trades Jack a handful of magic beans in exchange for the cow. Jack's mother is super pissed when she finds out. Jack tosses the beans on the ground in shame.
Later, the beans grow into a huge beanstalk reaching into the clouds. Jack climbs up the beanstalk and finds a castle with a giant sleeping in it. He robs the giant, taking money and magic items (traditionally a bag of gold coins, a goose that lays golden eggs, and a harp that plays itself), and the giant catches him. He flees down the beanstalk with the giant in hot pursuit. He gets an axe from his mother, and cuts the stalk down. It falls, and the giant dies. Jack gets away with his stolen loot and lives happily ever after.
The moral of the story is that people who screw up dream of miracles that give them a chance to redeem themselves through risky heroics to make it all better in the end. But for us GMs, the moral of the story is that you can give the players magic beans, and then later you can have them grow into beanstalks that lead to exciting adventures.
How do you use magic beans?
Magic beans are discovered, not created. During play, you will create loose ends. Here are some examples...
- The PCs are rude to a cranky nobleman in a memorable, amusing scene
- Their mysterious nemesis kills an innocent person
- One of the PCs got the Frost Shortsword off his wish list after killing a dragon.
- The PCs befriended a goblin scout, and the players really like him
If you're following my advice, you've already got good hooks built into the characters' stories and goals, and transition hooks built into your main plot. But just in case, you should keep a list of magic beans along the way. Watch for the following kinds of loose ends, and write them down.
Personally, I make sure to mention them in session summaries. That way I can go back and read my own summaries to find some magic beans I can use for future sky castle adventures.
You might keep a master list of plot hooks or plot ideas. In that case, write down the magic beans you drop into the story as possible hooks into your possible stories. If you keep a wish list of scenes or events, pair the wish list scenes with the magic beans you created (No campaign ever ties up all the loose ends, so don't feel compelled to address them all.)
If you're using something akin to my "two steps ahead" style of prep, you can go to your outline level notes every time you drop some good magic beans and see if they work for any of your future plot points, and pencil them in.
What makes for good magic beans?
Good magic beans are created in play, through one of two things:
Emotional Connections: Any time the players feel pathos about a person, place, or thing in your world, it makes for a good magic bean. This includes NPCs that they love or hate, magic items from their wish list that they really wanted and finally got, any property (players are mad about owning real estate!), or titles -- which is just a way of saying "status within an organization." In most plots, you're going to try to make the key NPCs ring with pathos for the players for core hooks integral to the plot, but sometimes minor characters strike a chord with them unexpectedly. These make great magic beans. Also, beloved (or dreaded, or reviled) NPCs from past stories can reappear as magic beans in later adventures.
Loose Ends: Sometimes in the course of a story, the PCs take actions for which there could be positive or negative consequences, but in the interests of moving the story along, you let it pass, for now... Positive consequences are when the PCs do heroic deeds and others want to thank them, reward them, join them, support them, tell stories about them, etc. Negative consequences are when the PCs take actions that harm others. On the Heroes and Hunters story rungs, typically the PCs' actions don't directly lead to negative consequences. But even on the hunters and superheroes rungs, the PCs' enemies actions can harm innocents, and the PCs might get blamed or at least asked for help. "Help! Your fated enemy, the lich king, destroyed our village!"
Finally, put it all together. Let's say you have the "magic beans" from the example above and you want to use them to hook into the adventure from my "Dungeons" post. The initial hook for this adventure is the murder of a Duke, with one surviving witness.
Bean 1: The PCs are rude to a cranky nobleman in a memorable, amusing scene.
Beanstalk 1: Use that nobleman as the one who was murdered. There are three witnesses. Two were found dead, and one fled. The PCs are wanted for the murder, because they were seen verbally abusing the nobleman a few weeks before. They need to find the witness to clear their name!
Bean 2: Their mysterious nemesis kills an innocent person.
Beanstalk 2: The murder of the two witnesses to the duke's murder shares all of the signs and trademarks of the earlier killing. The third witness may have information on their mysterious nemesis!
Bean 3: One of the PCs got the Frost Shortsword off his wish list after killing a dragon.
Beanstalk 3: The duke was beheaded with a short blade that left the wound cold to the touch and rimed with frost. In addition to being wanted in connection to the crime (see beanstalk 1), it implies a twin to the PC's weapon, perhaps a matched set for a dual-wielding ranger if they can track down the killer (Ooh! More loot!).
Bean 4: The PCs befriended a goblin scout, and the players really like him.
Beanstalk 4: Simply change the priestess of the silver flame to a goblin and make her the scout's sister. He comes to them begging for their help to find and protect her. Or else make the goblin scout the new Master of Spies for the Duke ("he's moving up in the world!"), and in the shame of his failure to protect his Lord from assassins, he comes to the PCs as a last resort.
The advantages of using the magic beans trick are that it ties up more of your loose ends, and makes the campaign world feel rich and interconnected. Plus, magic beans are hooks the players already care about, so you can draw them into stories organically, without even a hint of railroading.