I have formerly talked here about my single-sheet quick reference for refereeing. I was taking a look at it again and realised everything on it used d6s, except my small table of saving throws: a table with all 1st-level saves for each class in OSE Classic, plus another line for the saves of a Normal Human. Here's that table:

After realizing that, I had no choice but to, you know, change the d20 saving throws into the titular 3d6 Saving Throws, with similar odds of success. Here's the new table:

And for those curious, here's how the odds change by class and save, with added average for each:

Pretty close! And here's the table to convert from d20 to 3d6:

If you calculate all odds, none change more than 5% one way or the other (which translates to a +1 or -1 on the d20).

One thing to keep in mind if you ever want to use 3d6 saves is that how much a +1 or -1 is worth probability-wise changes drastically depending on where you are in the curve. From 12 to 11 means an increase in 12.5% on the probability of making the save, but from 8 to 7 the increase is only 6.94%.

And while we're talking about saves, remember:

You don't need HP. Just roll vs death if appropriate.

Cover art: Death Intoxicated by Percy John Delf Smith (1919)