[RPG] How to load polyhedral dice so they roll poorly?


My current GMing situation mandates I roll dice out in the open. However, I want some special loaded dice that'll roll poorly in case I need to save a PC or the plot. There are some caveats:

  1. Close inspection can't reveal that the dice have been altered.
  2. The balance shift should be just enough to make the roll appear to be bad luck.
  3. I need to use a full standard polyhedral dice set (d4 through d20).

How can I load dice so that I have a set of GM-only bad luck dice?

Note that I am uninterested in alternatives to loaded dice. I can't change this house rule so I can roll behind a screen. I can't introduce a plenthora of extra house rules and I also can't, for example, just lie and claim secret modifiers are altering these out-in-the-open rolls. In other words: this is not How can I fudge die rolls when they're made out in the open?

Best Answer

Three Suggestions:

First, if you are like most DMs I know, you probably own a fistful of any given kind of die. You can do something called a chi-square test to determine which die were manufactured imperfectly (hint: all of them) and might favor particular numbers. I would expect the odds to be slight, but perhaps an off-brand may be more unfair, one way or the other. An advantage to this approach is you don't need to introduce any new dice; you just favor one or another that you already own.

Second, you could try to find some weighted dice online. A quick search turned up some possibilities, but I haven't tried any of them so I can't back up any advertising with personal experience.

Third, many games provide circumstantial bonuses/penalties you can apply to a die roll to artificially, but legally, impact the odds.

An observation

Sometimes, the only winning move is not to play roll. As the GM in any game that has one, you have great control over what does and doesn't happen. If you know the wizard is at low health, perhaps the baddie simply attacks someone else, attempts a parley, regroups, runs away, or does something other than directly attacking the wizard. This technique can produce interesting story results, but be difficult to execute in a believable way. However, you are a participant in a partially luck-based game. Every time you reach for the dice, you should be prepared to accept anything they may show.