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:
- Close inspection can't reveal that the dice have been altered.
- The balance shift should be just enough to make the roll appear to be bad luck.
- 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?