I've had Highlander on the brain for the past few days, and recently finished reading through Reign... and had some ideas on how to handle Highlander style immortals in it. Thought I'd toss them out there for comment and/or just to get them out of my head. 

Immortals have a new trait, Quickening.

At character creation, a die of Quickening costs 10 points. If you don't start with Quickening, you can't buy any during play. Generally, you can only start with a single die of Quickening, but the GM may allow more if starting with higher point characters. You cannot have Expert or Master dice in Quickening. After character creation, you can raise quickening two ways: spending experience or slaying another immortal (a being with Quickening). Raising it with experience uses the same cost as raising a Company trait with experience (aka it's expensive!). See "Taking Heads" below for details on the other method.

A being who possesses Quickening is immortal, doesn't outwardly age much past maturity (or "first death", depending on your point of view), cannot have children, can surpass the abilities of mere mortals, heals from the gravest injuries, and can only be killed through decapitation.

Immortality, inability to have children, etc don't really come into play, so I'd just call it flavor (until an Immortal stays at the head of a company for generations upon generations... then it's just cool.)

Using Quickening to improve your abilities:
Each round, you can allocate quickening dice to increase one of the pools you wish to use (generally the lowest when performing multiple actions). A single die of quickening equates to a a single extra die rolled. You can also focus your power for better effects, for a cost a two dice a single expert die can be added to any pool, and for a cost of four dice a single master die can be added to any pool. This can result in multiple expert/master dice being rolled. Keep in mind that these expert/master dice will still be lost first due to penalties. These dice can also be allocated for non-turn based rolls, such as the daily natural healing rolls (which generally only come into play with very low quickening ratings, or neck wounds), and can be allocated while unconscious.

Using Quickening to heal:
Each round, any unallocated Quickening dice (not used to improve abilities) are rolled to represent automatic regeneration. A set heals W-1 in Killing or Shock damage to the location rolled. Waste dice heal Shock damage in the location rolled. Obviously, it can take a while to heal from multiple injuries. If conscious, you may take an action to attempt to direct your life force to a particular location, use the "called shot" mechanics to adjust your die pool and set a die to the desired location. An immortal who would normally be dead from accumulated damage is basically a corpse that slowly regenerates until enough damage is healed to become active again (at least one empty box in both the head and torso).

Taking Heads:
Striking at the neck must use the called shot rules (you cannot just use master dice or an expert die set to 10), setting the target location as neck / 10. Only Killing damage will suffice to decapitate someone. You must inflict a total of 4 boxes of Killing to the neck in order to sever their neck. Any damage to the neck that doesn't sever it cannot be healed using Quickening and must heal normally.

The Quickening!
After taking another immortal's head, you also take their knowledge and power in a crazy special effects extravaganza. Mechanically, if your victim's quickening rating is higher than yours, your quickening increases by one. If your victim's Quickening is equal to or less than yours, you gain a number of XP equal to their rating. Next, regardless of their quickening rating relative to yours, you may take some of their knowledge. Pick one of the victim's skills that they have at a higher level (*) than you, and increase your skill by one level (or upgrade a single die, per below).

(*) "Higher" could include a skill that has an expert or master die that you do not have an ed or md in, even if your actual level is higher. It may include an ed or md and still be a higher level than your skill. In either case, if the skill you select has a special die and you do not, instead of increasing the level, you may upgrade one of your dice to the type of special die the victim had. As usual, you cannot have both an ed and md in a single skill. If the victim has no skills higher/better than you, you get nothing extra.

Alternate idea for when quickening ratings are equal or lower: Instead of rating in XP, you get some XP that can ONLY be used to increase your quickening rating. This could be a static multiplier based on the rating, or you could roll the combined quickening ratings of victor and victim and grant XP equal to the height of any set rolled (with no sets still giving 1xp/level maybe), or whatever you feel gives you the speed/progression you want to see. Rolling a combined pool of both quickening ratings does give a better chance of a high quickening character gaining XP from a young or low quickening character, but the XP required to increase quickening at higher levels is rather pricy. When granting more than 1 XP per level, the XP should be limited in use to increasing quickening.

Holy Ground: Taking an immortal's head on holy ground could result in no-one gaining the quickening/power, or it could result in some terrible catastrophe (pompeii!), or it could just be a code that the immortal's follow with no actual game effect.

And... that's all I have. Obviously this is my interpretation of the setting, and depending on how many movies/shows you've seen you may have an entirely different interpretation.


Source: forum.rpg.net