Sunday, 30 December 2012

Equipment, races, hero classes, and probabilties

+Josh Tapley added a comment on one of my earlier posts about adding racial modifiers to some of the heroes:

"Thanks for the response, and a great point. I've been thinking about minor pluses for most things.   Like -1 Melee / +1 Ranged for a halfling."

I hadn't thought about racial bonuses before, but it's obviously easily done in the style of the equipment cards that the heroes are given at the end of the Tomb of the Lost King adventure.

But before we get too deep into discussion, let me just lay out a few of the basic mechanics on which Hero Kids is built:

•   Ranged attack distance is longer than a hero/monster can move in one move action
•   Magic attack distance is equal to the distance that a hero/monster can move in one move action
•   Heroes (generally) attack with at least two dice, and can usually also increase this to three dice in specific circumstances
•   Enemies generally have only one or two dice for their armor defense

Back on my Heroes Against Darkness blog I ran the probabilities for the opposed dice pool mechanic on which Hero Kids is based.

Here are the results for the opposed checks, with ties resolved in favor of the attacker.   The bolded areas show the expected probabilities for heroes attacking monsters, while the italicized probabilities show what happens when the heroes get up to four six-sided dice for their attacks.

Attacker's pool
(down the left)
1d6 2d6 3d6 4d6
1d6 58% 42% 34% 30%
2d6 75% 61% 53% 48%
3d6 83% 72% 65% 60%
4d6 88% 79% 73% 69%
5d6 91% 84% 79% 75%
6d6 93% 87% 83% 80%

As you can see from the probabilities, Hero Kids is quite generous in that the kids' heroes are generally successful in their attacks ~60%-~80% of the time.   The 61% success probability represents a hero's normal attack (two dice) against a strong enemy (an enemy with two dice for armor).   At the other end of the scale, the 83% success probability represents a hero's strong attack (three dice) against a weak enemy (one with only one dice for armor).   So far none of the enemies in Hero Kids have three dice for armor, however the ghost at the end of Tomb of the Lost King can only be hit with a natural six.

Increasing the heroes' attacks to four dice increases these probabilities to 88% against weak enemies and 79% against strong enemies.

At this point you're probably asking; "What is the point of all of this discussion of probabilities and mechanics?"   My point is basically that offering a flat +1/-1 dice for a racial bonus is a significant increase in the already high likelihood of success for the heroes' attacks.

With this in mind, I would recommend against offering a flat +1/-1 bonus for racial modifiers as these skew the probabilities too far in favor of the players, and lead directly to the sort of min-maxing that they're too young to have to endure... :-)

Instead, I would recommend coming up with situational bonuses that reflect the race's strengths and weaknesses (or just their strengths) or intermittent bonuses that the players can activate sometimes.   Here are some ideas:

•   If you've been attacked by two enemies since your last turn, you can attack with 1 extra dice.
•   You can move up to 5 squares in your move action.
•   Once per adventure you can ignore 1 damage.
•   Once per encounter you can swap places with an adjacent enemy.
•   You are sneaky and gain 1 extra dice when hiding.

All of these examples offer situational benefits, rather than flat bonuses.   They reward players who are paying attention, and they prevent excessive power creep in the game.

"I also saw that you added some magical equipment in the modules, which is something that I was planning to do as well."

Persistent equipment was something that came up in the playtesting, but it wasn't until one of the later adventures that I managed to include it in a meaningful way.   As I've discussed above, I've avoided flat bonuses for the equipment and favored situational bonuses which help the players, such as in these examples:

•   Once per encounter you can reroll 1 dice of an attack or defense.
•   Once per adventure you can add 1 damage when you make a successful melee attack.
•   The first time in each encounter that this weapon hits with a melee attack it deals 1 extra damage.

Let me know if you've got any ideas for more equipment with cool abilities.

"Do you have any forums setup to talk/share custom character classes?"

While I don't have a forum set up, there is a thread for Hero Kids over on RPGnet:

[Hero Kids] A D&D-like fantasy RPG for 4 to 10 year olds

I think I've covered most of the mechanical distributions of dice using the guidelines for creating heroes with the four dice method (page 17 of the PDF rules).   However, there's plenty of room to explore in the Special Actions and Bonus Abilities, as well as the possibility of introducing heroes with less or more health to compensate for having more (or less) dice to distribute for their abilities.   For example, a hero might have only two health levels (Hurt and KO) but would have five dice to distribute for their abilities (remembering that the first dice in magic and ranged abilities costs two dice).

Feel free to discuss hero ideas over on RPGnet (make a new thread if you like), or even here on the blog.