Ask any Dungeon Master what the most dangerous thing in a Dungeons & Dragons game is, and I’ll bet the majority will come back to you with “the players.” Players can range in power and abilities more than any monster and will always find the cracks in any system and crawl through. Players will think outside the box more often than not and will work around problems you might think they need to face head on. I can remember playing “Zelda: The Ocarina of Time” forever ago, and the most frustrating encounter was fighting a shadow mirror image of yourself.
That being established, perhaps a DM stuck with how to resolve an evening’s encounter can pull from this resource without worrying about level requirements, CR, or terrain. All one needs is the right setting.
The one drawback to something like this comes down to the same resource: the players. Some players can be very defensive about their characters and may not be open to sharing character information, or they may worry their character concept will somehow be violated or disrespected. This is sensitive ground. Tread carefully. However, with their cooperation and agreement, you could use this sort of encounter with rewarding results.
This encounter will require a little bit of preparation. Players may have private information on their character sheets like alignment or secret flaws. You may be able to get the players to more easily cooperate with the mechanics behind this encounter if you respect that privacy. Therefore, you should gather the players’ character sheets at some point and record publicly known information like ability scores, saves, AC, hit points, hit dice, and a few trademark abilities, attacks or spells. Create an alternate character sheet with this limited information and hold it in store for when you need it. When the time is right, you can spring this almost like a trap. Given the fact that this will use refined versions of the player characters themselves as the “monsters,” this encounter is also unique in that it could apply to any game system or setting.
Suggested level: Any, but be careful to scale any damage as appropriate. Remember,“the most dangerous game” is often “Man”… or in this case, the players.
Description: This encounter can be placed anywhere the DM wishes to imagine, but for the purposes of this encounter, we’ll place it in a dungeon environment. It’s generic enough that a clever DM could place this encounter into another setting like an art gallery, wizard’s inner sanctum, temple, or other appropriate place.
The players will enter a room, perhaps a 30’ cube, with reliefs carved into the walls showing figures in combat. In the very center of the room, hovering above a three-foot-tall podium of carved stone is a gem. This gem silently and slowly spins above the podium as if blown by a breeze unfelt by the player characters. The gem itself is massive, perhaps three inches in diameter and of an opaque black color. Each facet reflects the light of any torches or light spells used by the party, reflecting them about the room and filling the chamber with lights that dance over the carved reliefs.
For those interested in the wall carvings, a successful Intelligence/Investigation (DC:14) will reveal the figures in combat are exact duplicates of each other, right down to whatever weapon, armor, or method of combat.
The podium under which the gem hovers is carved to resemble two faces. One is calm and placid, and the other is very angry.
The gem itself is expertly carved (perhaps the appropriate artisan skill such as Jeweler, or a Guild Artisan or Clan Crafter of jewels, or a Rogue from a Thieves Guild expert in jewel thefts), and shows no physical means of remaining aloft. A successful Arcana check (DC: 12) will indicate some sort of Transmutation is in effect, as will a Detect Magic spell (no DC required). If the Detect Magic is actually cast, it will also reveal that the gem is a source of some sort of Conjuration magic as well.
It’s important to ask how the players are examining or investigating the contents of the room. The reason for this is clear: the second anyone touches the gem in any way (including throwing a bag over it), the next phase of the encounter will begin.
Once anyone touches the gem for any reason, black rays will shoot out and target each person in the room. Every target (player or NPC) will require a successful Charisma saving throw (DC: 17) or have their own shadows rise up to face them.
At this point, the DM will access the abridged character sheets as the “monsters” each face their own duplicate. A player who defeats their own duplicate can assist another player with their duplicate, otherwise risking attacks of opportunity from their own duplicate (and perhaps Sneak Attack in the case of a Rogue’s duplicate) by turning their back on their duplicate to face someone else’s prematurely. Each player’s shadow will always attack their host first and foremost above all other targets, disappearing if or when they defeat their host.
Should all the shadow duplicates be defeated, the gem will transform. It’s opaque black nature will clear, as will the magic suspending the gem in place, and the gem will become a normal and non-magical diamond. The evil magic will have flawed the gem, so despite its size, it will still retain a value of 2,000 gp.
Monsters: The player character shadows. This requires preparation as detailed in the introduction of this encounter.
Treasure: Should they players succeed, they will win a large yet flawed gem of 2,000 gp value.
Complications: Given that the player characters can be their own worst enemies, the concept of defeating the player characters is a real possibility. Also, given how much any player character can do, this encounter will require a lot of preparation on the part of the DM in creating the player character shadows, as a DM will want to trim down the number of spells or abilities to a few key and easy to run abilities that make each player character distinctive yet easier to run.
The players may well walk away from this encounter with an increased respect for their own abilities, and perhaps a newfound understanding of what the DM faces every time they pull out an encounter to challenge the player characters.