In my opinion, the game Category and Mechanic definitions are incomplete, inaccessible, ambiguous, and in some cases, misleading. This is unfortunate, because accurately searching on these fields can be extremely useful when researching games.
My detailed explanation follows.
DEFINITIONS ARE INCOMPLETE
Not all categories and mechanics have definitions. The definition usually appears as a pop-up when I hover my mouse pointer over a term. But when I visit Yahtzee Jr. and mouse-over the "Dice Rolling" Mechanic, a funny, pencil-thin, blue rectangle appears, clearly trying to tell me something, but too tongue-tied to get a word out.
DEFINITIONS ARE INACCESSIBLE
The Submit New Game Form and Advanced Search Form include a list of checkboxes for categories and mechanics. However, there is no way to see the definitions for categories or mechanics from these pages. Does "Dice Game" refer to games like Yahtzee and Craps, or to any game that uses dice? Since there's no obvious way to find out when submitting a new game, most BGG contributors are forced to either guess the correct value, or more likely, not bother trying at all.
DEFINITIONS ARE AMBIGUOUS
The definition for category Dice is:
"Category 'DICE': Rolling dice and using their results is a main component of this game."
Well, clearly Craps is a "Dice" game, and certainly Chess is not. But is Risk a "Dice" game? If someone asked me what kind of game Risk is, I would not seriously reply, "Oh, Risk is a Dice game," but BBG's definition can be easily interpreted otherwise; Risk does involve throwing a lot of dice. Then again, I can argue that the "main" component of Risk is capturing territories, and rolling dice is of indirect importance; merely a means of resolving battles and capturing those all-important territories.
In fact, BGG does define Risk as a dice game, but not Axis & Allies (a similarly structured game), at least at the time of this writing. Opinions, opinions!
Moving on, "Mechanics", in the context of board games, is defined as the "routines or basic methods, procedures, techniques, or details" of playing a particular game. Risk certainly includes a "dice rolling" routine, so I conclude Risk has a "Dice Rolling" mechanic.
Interestingly, Risk's BGG entry defines it with "Dice" as a category, but no "Dice Rolling" mechanic. Fools! It's the other way around! SO *I* SEZ!
DEFINITIONS ARE MISLEADING
Some definitions are outright misleading. Take the category "Racing", for example:
Category 'RACING': A rather nebulous category, players attempt to finish a sequence or task first.
Not only nebulous but also misleading. By this definition, clearly Memoir '44 is a "racing" game. The objective is to accumulate a specific number of "victory points" first. Similarly in Chess, the task is to "check" the opposing king, and the players race to complete this task first.
However, "Games > Categories > Racing" returns a list dominated by cars and horses.
With the end user in mind, I suggest a "racing" category search should return a list of only such Car Racing, Horse Racing, and Candyland-type games, because that's casual visitors' expectation. On the other hand, a new "racing" mechanic search could return that "nebulous" list (which probably includes half of all games in existence). Hopefully a new word would be used to avoid confusion.
I have three recommendations:
1) Clearly define all category and mechanic terms on the Submit New Game form. A pop-up window for each term would suffice. This pop-up window is already implemented on the game pages. This change will improve consistency across the BBG game database.
2) Clearly define all category and mechanic terms on the Advanced Search form and the "Games > Categories & Mechanic" pages. This change will make game research easier.
3) Define each of the category and mechanic terms using the following rules as a guideline:
The relationship between Games and Categories should be an "IS A" relationship (e.g., Craps IS A Dice Game).
The relationship between Games and Mechanics should be a "HAS A" relationship (e.g., Risk HAS A Dice Mechanic).
Making these changes will improve BBG as a research tool. Making them expeditiously will reduce the number of errors that will require correction in the future.
I SEZ SO!