Rolls an N-sided die M times, keeping the top P results.

Rollitude.js

var FORTITUDE = 1, WILL = 2, REFLEX = 3;
var Player = {
    "player": "",
    "name": "",
    "race": "",
    "classes": [],
    "fortitude": 0,
    "reflex": 0,
    "will": 0,
    "strength": 0,
    "dexterity": 0,
    "constitution": 0,
    "wisdom": 0,
    "intelligence": 0,
    "charisma": 0,
    "items": [],
    "skills": [],
    "spells": {
        "known": []
    }
};

Player.save = function(type, dc, modifiers) {
    var def = roll(20);
    console.log("Rolled,            " + def);
    if(type === FORTITUDE) def += this.fortitude;
    if(type === REFLEX) def += this.reflex;
    if(type === WILL) def += this.will;

    console.log("After base saves,  " + def);
    if(modifiers !== undefined) {
        for(var i = 0; i < modifiers.length; i++) {
            def += modifiers[i];
        }
    }

    console.log("After modifiers,   " + def);
    console.log(def + (def >= dc ? " succeeds " : " fails ") + "against DC " + dc);
    return def >= dc;
};

function roll(spots, total, count)
{
    if(spots === undefined || parseInt(spots) < 1) spots = 6;
    if(total === undefined || parseInt(total) < 1) total = 1;
    if(count === undefined || parseInt(count) < 1 || parseInt(count) > total) count = total + 0;
    var res = new Array();
    for(var i = 0; i < total; i++) res.push(Math.floor(Math.random() * (spots)) + 1);
    res.sort(function(a,b){return b-a});
    res = res.slice(0, count);
    var total=0;
    for(var i in res) total += res[i];
    return total;
}