Problem Statement

RPG   =   Role Playing Game.

You're running a tabletop RPG, and your players are creating characters. Each character has six core attributes: strength, dexterity, constitution, intelligence, wisdom, and charisma. One way of generating values for these attributes is to roll four, 6-sided dice (d6) and sum the three highest rolls, discarding the lowest roll. Some players like to assign values to their attributes in the order they're rolled. To ensure generated characters don't put players at a disadvantage, the following requirements must be satisfied: However, this can require a lot of manual dice rolling. A programatic solution would be much faster.

Write a program that:

Let's start with the solution:

#lang racket

(define (d6 . _)
  (+ (random 6) 1))

(define (best-3-of-4d6 . _)
  (apply + (rest (sort (build-list 4 d6) <))))

(define (generate-character)
  (let* ((rolls (build-list 6 best-3-of-4d6))
         (total (apply + rolls)))
    (if (or (< total 75) (< (length (filter (curryr >= 15) rolls)) 2))
        (generate-character)
        (values rolls total))))

(module+ main
  (define-values (rolled-stats total) (generate-character))
  (printf "Rolls:\t~a~%Total:\t~a" rolled-stats total))