Role-playing campaigns are genre affairs. Most fall into a few categories like “sci-fi,” “high fantasy” and “horror.” Regardless of the theme, players learn the rules of the setting. When a magic user throws a “fireball” in a “Dungeons and Dragons” campaign, no one is truly surprised. Magic is just another “fact” of this fantasy world.
Players start getting complacent. They start meta-gaming the setting and make decisions based on their assumptions.
It is at this moment in the campaign you should introduce an anachronism. An anachronism is “something or someone that is not in its correct historical or chronological time.” It is time for the AK-47. How the anachronism arrives in your campaign is up to you, but alternate worlds and time travel are some common solutions. That said, you cannot just drop the weapon into your world without some planning. Care must be taken to prevent a “plot disaster.” You have to carefully consider the rules impact of the item and the plot implications.
Rules are the easiest obstacle to overcome. I, the DM, am all powerful with the rules. The AK is a formidable weapon, so I decide that it attacks 10 times per round with 2d8 per shot. Yes, it is completely unbalanced, but I am planning to give it to the main villain. He is the final battle of the campaign and deserves a serious weapon. Now that the mechanics are out of the way, we move on to plot.
Just dropping the AK into the final battle is certain to draw howls of protest from your players. You need foreshadowing, vague certainly, but foreshadowing nonetheless. AK-47s are completely unheard of in a fantasy campaign, so the NPCs do not even have the vocabulary to describe it. A machine gun becomes a “steel wand” that “spits fire” and causes men to die “horrible deaths.” I really like the idea of PCs getting their descriptions 3rd hand from ignorant peasants. Keep them guessing as to the true nature of the item. At the final reveal, be sure to cackle maniacally as the party shouts in unison “The evil wizard has a gun?” Mmmmm …good times.
Because of the “mystery” aspect of anachronisms, they should be unique items. One AK-47 in the campaign is novel, 100 makes them just equipment. Anachronisms should never appear in a marketplace for sale, only taken as spoils of battle.
One final plot requirement of the anachronism is that it is disruptive to your world. A gun is clearly a tremendous advantage to an evil wizard, but this is a simple example. Historically, many technologies were disruptive and they never killed a single human being. Do not fixate on weapons, there are many other anachronisms that will liven up your game.
Here are a few ideas:
Precision clocks: allowed for precise sea navigation
Radio: instantaneous non-magical communication
Metallurgy: stronger weapons and tools
Using clocks as an example, any nation with a $5.00 Timex watch and a compass has a strategic advantage over any nation that does not. Precision time pieces are the only way to accurately calculate longitude. It is not an insignificant advantage. Entire armadas missed their destination by hundreds of miles before precise nautical clocks.
A final thought on anachronisms. To save yourself pain later, make certain that any item has a limited lifespan. Dealing with a captured AK-47 in the party for the next year of gaming could ruin the campaign. In this example, the solution is simple, the weapon runs out of bullets. Or the item requires maintenance or just breaks down from overuse. Perhaps a more powerful entity/nation desires the item and pays handsomely for it. PCs with an item capable of altering the balance of power makes for some fun role-playing moments.
This post used a “high fantasy campaign” example, but feel free to throw some magic swords at your sci-fi campaign, perhaps an wizard tries to conquer a distant space station with his magical powers. The opportunities are endless.
Have fun and remember when the players start screaming that you “cheated” when their starship trooper falls prey to a magic spell, just smile and blame me.
Trask, The Last Tyromancer