Now when you think about it, having a "blood bar" does make a certain sort of sense. After all, when you get hit by monsters, you lose blood, and any healing you take from others would have to somehow restore your blood to your body as well as sealing up all the holes in your flesh. Of course without healing, all those holes in the flesh would also prevent a warrior from swinging his sword around so freely, or at least make him limp a bit. But realism isn't really the issue here -- the idea of "blood" or "health" as a measurable quantity is just something we need as a symbol to represent the video game mechanics in an emotionally meaningful way.
A game like WoW can't possibly be as complicated as real life; it would hardly be as fun as it is if it were. Instead, it needs to use real life metaphors as an access point to get you involved in the game, while in the end it's still all about numbers. Stripped of metaphorical words like "health" (or "blood"), playing World of Warcraft might look a bit like this:
Player 4837 says, "I'll reduce your unit's primary points with my unit's special 'large-scale point reduction ability!' Pwned you!! haha!" only to be countered with Player 7490's response: "Oho! but my unit can use my secondary points to exchange for primary points, and make up for this loss! Noob!"Talk about boring! But underneath all the "fireballs" and "greater heals," this shifting of numbers around is exactly what we're doing when we play, no matter where we are or what language we speak.
In China, of course, the points and numbers are exactly the same, but it makes sense that the underlying metaphor would be somewhat different. For them, "adding blood" to a wounded teammate feels just as natural as when we say we are "healing" them -- but when you translate their "blood" metaphor into our language, it gets pretty weird!
Images come to my mind of healers like druids, priests, and paladins setting up blood transfusion posts, complete with beds and IVs, where adventurers need to come up and get themselves pumped up again in order to go back into the fray of battle. You'd have to ask the healer if they stocked up on "tanks of blood" from the regent vendor before joining you in an instance. Then, when I think about the Priest's "Vampiric Embrace" spell, that gives me all sorts of willies! I imagine actual blood changing bodies, and not just "health points," as we're used to.
Nonetheless, as strange as this metaphor is for us in our language, it can be an extremely persistent one for Chinese gamers. I was having a conversation with one of my Chinese friends who plays World of Warcraft, and he insisted that the health bar is red in China, not green. I was astounded that Blizzard would change their programming to be at all different from our American version, just to fit what Chinese are more used to. I asked my friend to send me a screenshot once he got home, which he did. It turns out he was mistaken -- the bar is green after all (I doctored up his screenshot above in order to help imagine what it would look like if we had a red blood bar instead of a green health bar).
Now, to be fair, remember that my friend has grown up his whole life with nearly every video game having a red bar for the characters' health, and images from youth tend to stick. Furthermore, it's called the "blood bar" in his language! It only stands to reason it would be red, right? I can think of countless times I assumed something only to be have it pointed out to me that the opposite was (quite obviously) true. This story with my friend demonstrates, though, how very strong such a gaming metaphor can be in the mind of the gamer, that sometimes the idea you have in your mind about something can be stronger than the actual evidence you see before you.
I wonder if some of the ways we play our games seem really strange when translated into other languages for other cultures around the world, and if maybe they could point out some obvious things we've never really noticed about ourselves. What do other cultures understand about Americans and the way we think from the games that we produce -- how do they interpret our cultural gaming imagery?