I am the Warden!!
Before I get started, a little inter-personalizing conversation. Apologies to the both of you (Hey, I have no delusions at this stage. The ENnie nominations just came out and I'm feeling a little "glass half empty" today...) for the lack of posts, but it's Medical Week here on Oprah. Luckily, the only thing I've been poked with is an acupuncture needle. And with an extra half-hour on the schedule before my last appointment (I'm getting hooked up to a lie detector to measure my stress), it's time to tell you about dice groups.
When I first set out to create a new system, there was no intention of making a dice pool game. In a sense, I still don't consider this a dice pool, but there's definitely the option to do so. In spades.
The Optional System provides players with up to 4 types of dice known as dice groups, each one consisting of a particular die type for maximum application. By restricting a certain die (such as a d6) to a particular dice group, you'll always be able to separate your trained dice (d6s) from your circumstance dice (d10s). Let's take a look, shall we?
Base Dice (d20)
Everyone gets to play with their d20s. All dice options are rolled with at least one base die, or 1d20. Base dice represent the abilities and odds for an average, untrained character to accomplish the simplest of tasks (generally the base options). No matter what happens, you'll always be able to roll at least 1d20 to get it done. But when everyone's rolling 1d20, you'll want something to turn the tide in your favour and that's where the other dice groups come into play.
When you roll a natural 20 on your base dice, it explodes like every other dice PLUS you gain 1 training point. Training points fuel your character and expand them in new directions, so that means the only way your character can get better is by rolling more dice.
Trained Dice (d6)
OS skills work a bit differently than most RPGs. Rather than providing you with an all-encompassing bonus whenever the skill applies, skills allow you to apply trained dice on a limited basis. For example, if you trained your character in the Swordhandling skill, you'd start with 2 skill uses of +1d6 trained dice; twice in a fight, you can add +1d6 trained dice to your attack roll. Once you run out of skill uses, you can't add those dice anymore.
Trained dice use d6s to increase the odds of explosion, making them one of the best dice considering you only have so many to go around. They are highly recommended for stunts and can be applied even after you've failed your active or opposed roll.
Power Dice (d8)
What would fantasy be without magic or a superhero game without flying around in tights. Power dice offer up a more permanent enhancement, unlike skills, with additional d8s. Depending on your training, you can gain access to powers and gain power dice to particular options. For example, if you have the wizard's Necromancy power (something for the converted 4e-OS playtest), you gain +2d8 power dice when you use a necromancy spell or target undead creatures. There are no limits to the number of times you can apply those power dice, but only when the conditions of the power apply.
Circumstance Dice (d10)
Trained and power dice assume you're spent the proper training to take advantage of more dice, but you cannot be trained for everything in advance. There will be many a time where you need just a little bit more to overpower your opponent and seize the day. That's my cleanser's job. Oops, sorry, TV was on. That's where circumstance dice enter.
Circumstance dice add 1d10s to any active or opposed roll - depending on the situation - based on environmental factors and tactical advantages. For example, ducking behind a tree grants +1d10 circumstance dice to any defense roll; hiding behind a brick wall grants +3d10 circumstance dice. These are many of the same modifiers we've all come to know and love in our games, yet I'm hoping for a little more from these suckers. Rather than simply relying on the Director to tell you when these dice apply, I'm still working on a method for adapting the situation to your favour and cashing in points/chits/whatever to redeem additional circumstance dice. More to come if this works out.
What? No d12s or d4s?
Please, cousin, don't be rediculous. Of course these dice apply as well, but not in dice groups. d12s rarely explode (far less than d20s, despite probability's demands) and d4s are better off rolled in pairs because of how often they explode. They are available through individual bonuses at this point in the game and this may very likely change as time goes on. There's nothing to stop additional dice groups from forming for unique campaign styles and the like - I'm just hoping it's nothing simple and face-slapping I should have seen earlier on. For now, we'll call them "bonus dice." Pack them up, you'll use them sooner or later.