As a game master, I historically steered clear of heavy use of luck during my Dungeons & Dragons games. I tended was for the plot and what happened in a game to be shaped by character actions rather than pure luck. Recently, I chose to alter my method, and I'm truly happy with the result.
An influential actual-play show features a DM who regularly asks for "luck rolls" from the adventurers. The process entails choosing a type of die and assigning potential outcomes tied to the roll. While it's fundamentally no unlike using a random table, these are devised spontaneously when a course of events doesn't have a predetermined conclusion.
I chose to experiment with this approach at my own session, primarily because it appeared interesting and presented a break from my usual habits. The results were eye-opening, prompting me to think deeply about the ongoing balance between pre-determination and spontaneity in a roleplaying game.
In a recent session, my party had survived a city-wide battle. Later, a cleric character inquired after two beloved NPCs—a pair—had lived. Rather than deciding myself, I asked for a roll. I instructed the player to make a twenty-sided die roll. I defined the outcomes as: a low roll, both would perish; a middling roll, a single one would die; on a 10+, they both lived.
Fate decreed a 4. This resulted in a profoundly emotional sequence where the characters found the corpses of their allies, still united in death. The group held last rites, which was uniquely meaningful due to previous story developments. As a final reward, I chose that the NPCs' bodies were strangely transformed, showing a magical Prayer Bead. By chance, the item's magical effect was perfectly what the group lacked to solve another critical situation. It's impossible to script this type of serendipitous coincidences.
This incident led me to ponder if chance and spontaneity are truly the core of D&D. Although you are a meticulously planning DM, your skill to pivot may atrophy. Groups frequently find joy in ignoring the best constructed plots. Therefore, a effective DM needs to be able to think quickly and invent scenarios on the fly.
Utilizing luck rolls is a excellent way to develop these abilities without straying too much outside your usual style. The trick is to deploy them for small-scale situations that won't drastically alter the campaign's main plot. To illustrate, I would avoid using it to determine if the king's advisor is a traitor. Instead, I would consider using it to figure out if the PCs arrive just in time to see a major incident occurs.
Luck rolls also serves to make players feel invested and cultivate the sensation that the game world is alive, evolving in reaction to their choices in real-time. It reduces the sense that they are merely characters in a DM's sole narrative, thereby bolstering the collaborative nature of the game.
This philosophy has historically been embedded in the game's DNA. Original D&D were filled with encounter generators, which made sense for a game focused on exploration. Even though contemporary D&D often focuses on story and character, leading many DMs to feel they must prep extensively, this isn't always the only path.
Absolutely nothing wrong with being prepared. Yet, it's also fine no problem with relinquishing control and allowing the rolls to guide minor details instead of you. Direction is a major factor in a DM's job. We use it to run the game, yet we frequently find it hard to release it, in situations where doing so might improve the game.
My final advice is this: Do not fear of letting go of control. Experiment with a little randomness for inconsequential outcomes. The result could discover that the unexpected outcome is significantly more memorable than anything you might have planned on your own.