How to model opposed rolls in Anydice?

Question

I've seen there are quite a lot of brilliant people on this board answering questions about Anydice. I am hoping somebody will be kind enough to answer this one too.

I want to use anydice to figure out the probability of success with opposing dice rolls. For example, 1d6+1d8 (test roll) vs 1d10+1d4 (challenge roll). The challenge roll determines the target number. If the test roll meets or exceeds the challenge roll, the attempt succeeds.

How do I set that up in Anydice?

Answer 1

Anydice supports conditionals

Anydice can do this with the conditional operators (e.g. > < >= <= = !=). From the documentation page:

AnyDice allows you to compare two values, to check whether a certain condition is true. If so, the result will be a 1, otherwise a 0.

Therefore the simplest program you can make to do this is:

output (1d6+1d8) >= (1d10+1d4)

You can see this program here. Using brackets around the dice causes them to be treated a one distribution. >= is the symbol for 'greater than or equal to' which is the same as your 'meets or exceeds' condition. If you wanted simply 'exceeds' use > for 'greater than' instead.

You could easily make this into a function like this but it provides little benefit over the base program.