A new game system in the making...

So I've been thinking of a totally new game system.  Yes, that means ditching my beloved, overhauled, Homebrew version of rolemaster and going with something new.  Something rules-light (actually my Homebrew system is very rules-light), and as story-focused as I have a penchant to be.  It'll be interpretive, because that's the direction I've always been heading (and largely encompassed).  And its going to feature:

d10s! - cos I have a bag of 'em.  Plus they just smack of RPG better than a d6.

It's going to be a dice pool game.  Because I think picking up a fistful of dice, and rolling them all is fun.  Plus that gives a lot of freedom in terms of throwing in extra dice for particular reasons... luck points, fate points, bonus dice, blah blah blah.  Don't worry, I'll expand on all this in another, more lucid post.

It's going to have bonuses to those dice.  So the player will end up rolling xd10+y... i.e. say you have three ranks in a skill, thats 3d10. A basic success chance is a 6 on any of those d10.  The harder the action - and several elements come into play there - the higher than success number is.  But a player can modify their rolls in a number of ways, and add dice to the pool in a number of ways.  So another example might be: try and get 12 or more on 6d10+3.  i.e. a player need only get a 9 or more (with the +3) to score 12 and succeed in that action.

On top of that, I want to include a d20. For no other reason than a d20 for me (probably because I cut my teeth on D&D, back in the day), signifies roleplaying.  Despite the fact that I have not used a d20 in any of my games for years... decades even.  When that 20 comes up, its a special moment, and one I want to include.

So the d20 will work like this:  You roll a d20 as a modifier to any action.  It signifies critical success... or failure.  It's the 'tweak' die.  The higher or lower the number indicates a tweak to the success or failure of the dice pool.  Furthermore a critical is obtained when a 20 is rolled (or a 1 in the sake of critical failure).  At the GMs discretion these numbers may be modified - i.e. a critical is afforded on a roll of 19 or 20, failure on a 1-3 etc. Regardless of a critical, if the tweak die is higher than twice the number required to succeed, the player earns a bonus point from the action which they may use in a future roll.

If a 20 is obtained and the dice pool has been a success - then the action is deemed to be a critical success. In this case the result is extremely beneficial to the player and they get a bonus die and bonus point (which can be added to a future dice pool), i.e. a 1d10+1.  The bonus die and the bonus point are considered separate entities and do not need to be used together.  These bonuses derived from critical success are referred to as being 'on a roll'.

If the dice pool (xd10+y) roll was a success, but the tweak (d20) roll was a 1 indicating critical failure, then the action still succeeds, but the player is left in an awkward position.

For example, a PC attempts to make a jump between rooftops.  The player has 4 ranks in jump so gets to roll 4d10 by default.  As a standard manouevre a roll of 6 or more on any of the dice would indicate success.  However the distance is quite far, so the GM states a roll of 7 is requried. The GM also determines because they are being chased (+1), are wounded from a previous encounter (+1) and its raining (+1); the action is complicated by a further +3, resulting in a 10 being the success marker.  The player determines that this is an essential action for their character, and from their bonus pool adds two more dice and two more points to the equation.  So they're intending to roll a 6d10+2.  The +2 means the result of any dice is raised by 2. So now the player has 6 chances to roll and 8 or more, with 8+2 = 10 = success.  They roll and get and 8 and a 9 (as well as some lower numbers) and so success has been achieved!  However, the d20 tweak roll they make at the same time comes up 1.  This means that despite them having made the jump, something bad has happened.  To determine how bad, the GM looks at the lowest number they rolled - in this case a 2 - and interprets that as them having taken some damage from a poor landing.  A 3 or 4 may have indicated some non-essential piece of equipment was damaged from a poor landing.  If a 1 was present, then maybe something important was dropped into the street below.

In this way perfect flexibility can be brought to bear on interpeting the outcome.  Such rules-light games are fast to play, not bogged down by multiple table checking, and the mechanics hinge upon the imagination of the GM and the players - which is what makes roleplaying so special.  Such rules-light systems harness what is special about Pen & Paper, and what makes it a unique form of entertainment -  i.e. a collaboration of imaginations.

On with the example: if the outcome of such an action fails - nothing 8 or above is rolled, but the tweak die comes up as a 20, it means the action failed, but something nevertheless beneficial happens.  In this example, the PC does not make the jump, misses the other rooftop and plummets down, but lands in a passing haycart.  Again the GM can take a look at the dice pool rolls for some inspiration or guidance.  Because this was a critical success the GM looks at how high the dice were ( though clearly not enough to warrant success in the desired action).  In this example we can say the player had terrible rolls, nothing above a 3, so the GM decides that the passing cart was actually transporting manure, not hay, and the PC is now rather stinky!

In the case of very poor dice pool rolls resulting in a failure of the attempted action, and a critical failure (1) generated by the tweak die, the PC is in a rather tricky situation:  They didn't make the jump and suffered a critical failure to boot, which could be translated as landing badly in the street below.  The intrepetive scale here, I would suggest, is based on what the 'scene' was trying to deliver.  In our example the PC was being chased across rooftops, so the ultimate failure here would be capture.  So this is essentially what is delivered by a critically failed action.  However, the GM does have a requirement to present an interesting, atmospheric and thrilling story.  So whilst they can suggest the player falls to their death, I would suggest avoiding that outcome in all but the most dramatic moments.  I.e. if they 100s of feet up and fell, it might be difficult to realistically avoid death.  And now we come to a potential cardinal sin of GMing.  Despite the fact that IMHO PC deaths should be rare and handled with care, they MUST be delivered if the situation requires it.  One cannot shy away from these moments.  Because nothing ruins atmosphere and verisimilitude faster than GM intervention.  By that I mean when a GM unrealistically pulls a PC out from a certain death situation.  If players feel they cannot die, it removes risk and tension, which results in a lack of excitement and a lack of atmosphere.

In the above example of a critical failure, the interpretive scale has PC death at one end, and something along the lines of a sprained ankle on the other, with broken bones, unconsciousness and capture somewhere in between.  As a GM, one should strive to deliver the next thrilling scene, which in this case might just be the PC hobbling off down a dark alley, having evaded the pursuers (as they're on the rooftops above) but now the PC is wounded and in a bad neighbourhood.

These, as basic mechanics, I think will be a lot of fun. They are of course intended to work for non-combative actions.