Role-playing Games Stack Exchange is a question and answer site for gamemasters and players of tabletop, paper-and-pencil role-playing games. It only takes a minute to sign up.
Sign up to join this community
I am looking for a way to make my players use their abilities more creatively and efficiently. I thought that, if they faced copies of themselves who rely on their current abilities would make them think in a new, different way. However it seems like a neat idea to me, I am unaware how this could be accomplished.
If it is important the ECL of the characters, that would be "copied" varies from 24 to 27.
A mirror of opposition (DMG 262) (92,000 gp; 45 lbs.) does pretty much exactly what you want:
This item resembles a normal mirror about 4 feet long and 3 feet wide. It can be hung or placed on a surface and then activated by speaking a command word. The same command word deactivates the mirror. If a creature sees its reflection in the mirror’s surface, an exact duplicate of that creature comes into being. This opposite immediately attacks the original. The duplicate has all the possessions and powers of its original (including magic). Upon the defeat or destruction of either the duplicate or the original, the duplicate and her items disappear completely. The mirror functions up to four times per day.
However, the mirror is, potentially, infinitely exploitable—be careful introducing it into your campaign, and adjudicate carefully that word defeat.
D&D is a world of magic.
You can have your bad guys do whatever you like. Have some nemesis who has specialized in creating temporary evil doubles like you described. You can say its some special npc only prestige class (Which you don't need to detail, it just does whatever you want it to do).
Don't let mechanics ruin a good story.
