As discussed previously, I recommend using the High Concept (discussed on pp. 31-33 of FATE Core and p. 8 of FATE Accelerated) to cover three important components of Blue Rose characters – Nationality, Race, and Role. All of these are covered in detail on pp. 54-74 of Blue Rose, with additional information in the Blue Rose Companion.
There are some definite advantages to just winging it when it comes to High Concept. Because High Concept is meant to be a very broad catch-all for what your character is good at, under most circumstances I would recommend leaving it open ended and simply consulting the Blue Rose rulebook occasionally when necessary for clarification. However, this can also make for some problems and disagreements as the campaign progresses if, for example, several players have a similar High Concept (for example, several Aldin Humans) and have differing interpretations of what that means. In the end it is up to each GM to plan things out based on the needs and play style of their group – some groups might be totally OK with this, while others may need some structure.
The various nationalities, races, and roles in Blue Rose are packages that define a character as being good at certain things and having certain abilities based on their background and profession. FATE attempts the same thing, but comes at it from a different direction, allowing players to use a few words or phrases to define what their character is good at and calling that their High Concept. The High Concept is in effect a sort of “Super Aspect” that defines the character very broadly, while Blue Rose uses several different background packages, each of which defines the character more narrowly.
One minor note – in Blue Rose, nationality is really only an add-on for the “Human” racial package. A rhy-cat is a rhy-cat regardless of where it grew up. This, however, struck me as going against one of the fundamental principles of romantic fantasy – egalitarianism. A rhy-horse growing up in the Islands would be exposed to Islander society and would differ from a rhy-horse growing up in Aldis. So for me, race and nationality should be separated. Whether.
The best way to start defining the High Concept is to look at the packages from Blue Rose. These consist of favored skills and favored feats in most cases (though in the case of some of the nonhuman packages they can be far more extensive). For each package I will let the character choose one of the favored skills (or the nearest FATE Core equivalent) to be able to modify – under any circumstances – for each package. In addition, between the three packages I will allow the player to choose one appropriate feat to turn into a stunt (for more on this see FATE System Toolkit pp 12-14). Note that it is certainly possible to allow for two, or even three stunts to be connected to the High Concept – I am limiting it to one in order to keep characters from becoming overly complex, but it is really up to each individual GM to decide how many stunts should be connected to the High Concept. For nonhuman races, which have lots of additional benefits, add each benefit but balance it out with a serious compel.
I’ll be adding my ideas for defining the Blue Rose series of High Concepts later, both for FATE Core and FATE Accelerated. Before then however certain other concepts such as skills and magic need some consideration and work.