Revised Last-Minute Keys and Locks

My random keys post from the other day has keys break off in locks when snake eyes (double 1s) are rolled when testing the key in the lock. This means that a key that doesn’t match at all (iron key in brass lock) has no chance of fitting and no chance of breaking.

For other keys, the chance of breaking goes up as the chance of fitting goes up.

# matches	key fits	key breaks
1	33.33 %	0.00 %
2	55.56 %	2.78 %
3	70.37 %	7.41 %
4	80.25 %	13.19 %

This is because I usually prefer increased risk being paired with increased chance of success. But if I wanted it to be more simulationist, making keys less likely to break if they match more precisely, there’s another way to do it:

When attempting to use a key to unlock a lock, roll 1d6 for every keyword on the lock that does not have a match. Example: the red crystal key used to unlock the blue crystal door has one mismatch, so roll 1d6. If there are no matching keywords at all, roll a minimum of 2d6. Roll 1d6 if the key matches perfectly. 

If all of the dice results are 5+, or all 6s if the key has no matching keywords, the key fits the lock and opens it. Otherwise, it doesn’t. If the key doesn’t fit and snake eyes (double 1s) are rolled, the key breaks in the lock.

This means that a key that matches precisely has no chance of jamming the lock. but the maximum chance of being the correct key is 33%, with the chance going down the less precise the match. Not sure I want the chance to be that low, but I’m considering it. It could be helpful for some of the other ways I’d like to use this mechanic.

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