Whether to show numbers or hide them in any game experience is a debate that has raged since people first starting beating up on each other with little pixellated characters, both from within game teams as well as from without. There is, of course, no absolute right answer. That being said, I will now go on to make bold, unilateral declarations on the matter.
At the start of my career, I was a big fan of hiding the numbers, and hiding the math that manipulated them. I figured it was because I liked realism, or a misplaced belief that hiding the numbers would create greater immersion. In the long run, though, I realized that it was because I was a rookie designer and that I was afraid to let other people look under the hood. My opinions on the matter have changed quite a bit, as I’ve grown more confident in my designs, and more willing to take player input into my designs.
Whether or not to show numbers depends a lot on the sort of game you’re making. If you’re making Doom, or God of War, showing the numbers is probably a mistake, as most attacks will be very different from each other, and players can discover via experimentation which are the most powerful and which combo of the others in a meaningful degree. However, the reward curves for RPGs and MMOs make this difficult, as there is finer granularity between rewards. We have to give away so many rewards over the course of 50 levels/200 hours/[Enter Your Max Play Experience Here] that we are forced to give much, much smaller rewards, such as items that offer only a 1% to your damage.
The actual shape of your reward curve makes this more relevant. The flatter your advancement curve (i.e. the closer in power that a MAXED character is to newbie, which also happens to mean the more skill-based your game is), the smaller these rewards can be (going down from, say, 1% to .1%). When this happens, your rewards will be imperceptable to the player from a feel perspective, and he will need hard data in order to make intelligent decisions. If you don’t show him this data, these rewards might as well not exist at all.
Many number-hiding advocates say that showing numbers increases the player’s obsession with numbers. I’ve actually found the opposite - that not seeing numbers can drive people nuts, because they feel they cannot make intelligent decisions. I may not actually know what’s better in WoW, +10 stamina or +10 intellect, but at least I could take a swing at it. As opposed to when I found the item that said a ‘Slight Improvement to Spell Damage’. What the hell does that mean? It is almost impossible to feel like you’re making a tactical decision when you see something like that. When you know that your +10 ring makes your +9 ring obsolete, you know instinctively what to do. If you don’t, then you are obsessing over mechanics and information that is denied to you. And frustration is the number one breaker of immersion.
Hiding the numbers in an MMO goes on to have other ripple effects. For one thing, the hardcore are going to figure it out anyway, they always do. This can be percieved by some as a good thing — an interesting elder game to keep a community occupied — but it also expands the gap between the hardcore player, who knows where to seek out this information, and the casual one, who plays solely based on the information on his screen.
Also something that no designer can ignore with good conscience, but hiding the numbers just creates an endless number of customer service calls. On Meridian 59, we had a random chance that your players’ skill would go up when you used it. Because this mechanic was opaque to the player, we had a huge number of CS calls from players who were convinced that their skills were ’stuck’ somehow, as if some dirt had gotten into the random number generator.
And let’s not forget the open-source principle: exposing your data to sunlight is a great way to expose bugs and imbalances. Of course, you have to be thick-skinned enough to be called a moron by a few thousand people, but the end result is almost certain a stronger, more stable game - as well as a community devoted less to the mechanical problem of how it works, and more to the tactical problem of how to play it. See Elitist Jerks for a great example of that.
So I think that showing numbers is the right thing to do in an MMO, most of the time. Still, I also think that too many designers make games with too many numbers - too many variables for players to track, especially low-level players. Having a manageable amount of information, and presenting that information to the player in a digestable fashion, is the responsibility of any designer who chooses to lift their hood for any newbie to take a gander.
