Opposition Table
Also known as the Resistance table.
To be honest, I have not found a reason to use this table yet, but here it is.
The
table is a simple formula, ( your stat - opposed stat ) * 5 + 50.
If you need opposed percentages, it would be ( your skill - opposed skill ) + 50.
If you would like to buy a printed copy of this table from Chaosium, you can
check
here. I bought a couple for my collection, but I have yet to use them.
You can also find a nice resistance table on page 384 of Basic Roleplaying, along with a Skill
Results Table that I keep meaning to use.