Quoting MHJeffries, reply 2
While we're adding bonuses to cosmetics, why not give a fire damage bonus for having red hair, a research bonus for beards, and a diplomacy bonus for green eyes?
While I do agree that some people (don't care if most or just a few) don't like the idea of the coat of arms having bonuses of any kind and that's fine as we are just suggesting things here, I fully agree with myself when I say that your examples are quite bad to formulate your disagreement with the idea.
I'm happy you and yourself could come to agreement on your dislike for my examples! If they don’t float your boat I'm sure we could think up some others that would.
My point was that applying bonuses to any cosmetic choices (be they the coat of arms, physical features of the sovereign, etc) will likely result in many players making choices not based on some RP character/kingdom design concept, but because of the bonus it provides. It is inevitable that some bonuses or combinations will be seen as better than others, and so some symbols will show up more often. Personally, I’d rather see a variety of coats of arms than everyone using a black camel surrounded by fire, on a background of white and green vertical stripes (or whatever) just because it happens to be the most powerful combination.
The perfect example of the type of system this would result in is the game Spore where certain types of body parts gave different bonuses. I don’t remember exact numbers, but the point was that if you wanted a powerful critter, you were limited in what you could choose to get the best stats. While there were maybe 20 types of hands, only a few made for the optimal critter.
Perhaps a coat of arms in itself won't give a bonus, but a bonus could grow over time. If you had an item, the Royal Banner, which you could choose to send with an army into battle, then that banner might accrue benefits over time as it participates in victories. Depending on the odds of the battle, of course. So if you take the banner into a tactical battle with the odds significantly against you, and yet you prevail, then the banner may in the future give some morale boost to any army in which it resides.
I like this idea. It’s not tacking bonuses onto actual symbols but to an items that can be won and lost.