check: Work with skill checks' probabilities and DCs
In droll: Analyze Roll Distributions

Description Usage Arguments Details Value See Also Examples

These are simple functions that manipulate probabilities and DCs for skill checks. check_prob() calculates the success/failure probability of a check with the given DC. check_dc() calculates the required difficulty class so that a skill check has the given success/failure probability. See below for more details.

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check_dc(roll, p, success = TRUE)

check_prob(roll, dc, success = TRUE)

`roll`	A roll expression (e.g., `2 * d6 + 5`) or a data frame returned by `r()`.
`p`	The probability of success/failure of the check (or attack).
`success`	Whether to aim for success (the default) or for failure on the check (or attack).
`dc`	The difficulty class to beat for a skill check (or the armor class to beat for an attack).

These functions hide the complexities of the roll family so users unfamiliar with R's d/p/q/r notation can get quickly up and running with the package. Since attacks and checks work in the same way (i.e., success means rolling a value higher than or equal to a certain threshold), there are no attack_*() functions.

For more details on roll expressions, see r() and the Dice S4 class.

A numeric scalar.

roll, r(), Dice.

# Probability of d20 + 8 passing a DC 15 skill check
check_prob(d20 + 8, 15)

# Probability of d20 + 8 missing an AC 15 attack
check_prob(d20 + 8, 15, success = FALSE)