The 13th Age RPG is one that introduced (or maybe just introduced me) a number of interesting, unique (I think), and very portable mechanics/rules. I've previously discussed the awesomeness of the One Unique Thing, a mechanic that takes basically zero effort to port into any other RPG and just about guarantees that the players and their characters will be more connected to the game world. The OUT is hardly the only mechanic of note though, so let's take a look at another.
The Escalation Die could just as easily be referred to as an escalation counter, but since a simple six sided die is the perfect tool to represent this mechanic at the play table it's name is plenty appropriate. During combat in 13th Age things escalate each round after the first, the die is used to track this number from round to round. The die is set to "1" at the start of the second round of combat, and generally advances with each round until it hits "6" at which point it does not increase further no matter how much longer the combat goes, or the combat ends at which point it is reset to zero. The value of the escalation die is added as a bonus to PC attacks during combat, this bonus is not given to NPCs or monsters, and so as combat progresses the characters will tend to hit more frequently. If the GM feels like it is appropriate based on the party's actions they can choose to not increase the value of the die at the start of a new round. This is used largely if the players are avoiding combat, or otherwise not driving the encounter aggressively.
Since 13th Age is a d20 based game the bonus provided adds roughly +5% per point to a character's chance to hit in combat. This ensures that as combat progresses the characters will hit more frequently, and this in turn helps to drive the combat toward resolution rather than allowing it to stagnate or drag on. In addition, certain effects and abilities cue off of the Escalation Die, working differently depending on it value, becoming available for use only when the die is a certain value, or, as in the case of fear, preventing the target from using the Escalation Die bonus.
While 13th Age is obviously designed from the ground up to take advantage of the Escalation Die mechanic the basic premise is one that can be moved to many RPGs. Let's look at a few examples taken both as written and with some interpretation.
Not that Cypher needs a boost to make combat move faster as it is generally a quick moving system, but if one were so inclined ... Using the Escalation Die as written each round after the first would see a bonus to attack rolls (and possibly defense rolls if the GM so desired, though I don't think that is in the spirit of the rules). After the die gets to "3" this effectively becomes a free level of effort to "hit", and at "6" it is two free levels of effort to hit. This will definitely give characters a boost, and free up their ability to spend effort on damage boosts late in the combat. At lower tiers the Escalation Die will have as much impact on combat as effort, possibly moreso.
Dice Pool Systems (White Wolf, Shadowrun, etc)
Dice pools aren't the best place to add a value to the roll, because when you are tossing 5-15 dice each roll that's just a lot of tedious math. Instead treat the Escalation Die (know what, I'm gonna start using ED from here out) value as a straight bonus to the die pool. If you are rolling six dice normally and the ED is a "3" you add three dice for a total dice pool of nine dice, roll as normal after that. It's quicker and will still have an impact on the end result. I don't play any of these systems anymore (its been a couple years at least) so I cannot say how much 1-6 extra dice will impact a given roll, though I would image that it will largely depend on how many dice you start with. Adding six dice to a pool of six dice is much bigger than adding six dice to a pool of fifteen.
As used by Green Ronin's Dragon AGE RPG the AGE system uses 3d6 for all tests (rolls for success/failure). Their mechanic goes to rolling two dice of one color and one more of another color. The odd die is the Dragon Die and makes stunts happen (I discussed this mechanic in detail here). Adding +1-6 to each roll is certainly an option, it will help the PCs hit more often and it will take those crummy rolls that would have been a stunt if they had hit (but didn't) into legit hits that generate stunts. That's probably the simplest way to use the ED for AGE, but I have another idea.
What about adding the ED value to the stunt points generated by successful Stunts? Adding 1-6 more stunt points is pretty huge, especially at the back end where you could double or more the number of points available. Having six points available makes for a memorable, big hit, bit potentially having 12 points could make for some truly jaw-dropping awesome stunts.
But wait, I can go further, why not give every PC attack stunt points equal to the ED? If they hit but don't stunt they still get some points to play with, and if they did stunt the add those points. In the 4th round of combat successful hits (or spell casting checks) will automatically generate 3+SP. If you want to encourage fast aggressive combat that's the way to do it. Characters will be able to boost their damage, pierce enemy armor, strike multiple foes, and the like with greater frequency, driving combat to resolution quicker, and making things far more exciting in the process.
I haven't tried porting the ED into another game system yet, so I don't actually know how well it will work. That said, I like the idea of a bonus that applies across the board to PCs to help push combat toward resolution faster. As a rule I think combat should be quick and exciting, but once an encounter goes beyond a certain length that excitement starts to wane, as the encounter turns into a grind.
Of course the ED need not be a d6. For Cypher I could use a d4 and limit the upper end of the bonus to a free level of effort with a further +1. While a system that uses large dice pools might want to go to a d8 or even a d10.
I'd be interested in hear from anybody who has ported the ED from 13th Age into another game system, how they did it, and how well it worked. Likewise, other ideas for how to implement the ED mechanic into the above systems in a way I did not describe would be interesting.
Note: You can find a copy of the 13th Age SRD at www.13thagesrd.com