RpgCharDF <- data.frame(Name = character(),
                        Level = integer(),
                        ClassChar = character(),
                        Race = character(),
                        HP = integer(),
                        Attack = integer(),
                        Resist = integer())

RPGcharacter <- function(name, level, rpgClass, race, HP, attack, resist){
    value <- list(name= name, level = level, rpgClass = rpgClass, HP = HP, attack = attack, resist = resist)
    attr(value, "class") <- "RPGcharacter"
    value
}

Artur <- RPGcharacter("Artur", 22, "Warlock", "Dwarf", 130, 12, 3)
Dawid <- RPGcharacter("Dawid", 1, "Homeless", "Gnome", 20, 2, 1)

RpgCharDF <- rbind(RpgCharDF, Dawid)
RpgCharDF <- rbind(RpgCharDF, Artur)

Warning in `[<-.factor`(`*tmp*`, ri, value = "Artur") :
  invalid factor level, NA generated
Warning in `[<-.factor`(`*tmp*`, ri, value = "Warlock") :
  invalid factor level, NA generated

NAME  Level RPGClass   HP  ATTACK  RESIST
1   Dawid   1   Homeless    20    2      1
2   NA      22  NA         130   12      3