To echo the points made by John, and others above, you cannot expect to produce an achievable design document without either:
a) having a decent knowledge of game development yourself, or
b) working very closely with people who do have that knowledge from the start.
If you don't, you risk having a design document that is a wish-list, is un-realistic, is un-achievable, will prove to be flawed, will result in project failure, or incurs exorbitants costs.
It's back to that argument about a design document simply saying "It'll have deformable scenery too", without any understanding of what that adds in gameplay terms, or the implications in technical terms. It's that understanding of the cost / benefit equation; where to make sacrifices in your vision (e.g. drop deformable scenery), and where to make quick wins (e.g. support for more input devices).
Okay, so I don't have a brilliant track record in game development, but I *do* have a very good track record in IT projects, and to some extent it's the same principle. The best visionaries are those that have grown into the role. (They're also those that will acknowledge their weaknesses and get input early on in the areas they don't know).
a) having a decent knowledge of game development yourself, or
b) working very closely with people who do have that knowledge from the start.
If you don't, you risk having a design document that is a wish-list, is un-realistic, is un-achievable, will prove to be flawed, will result in project failure, or incurs exorbitants costs.
It's back to that argument about a design document simply saying "It'll have deformable scenery too", without any understanding of what that adds in gameplay terms, or the implications in technical terms. It's that understanding of the cost / benefit equation; where to make sacrifices in your vision (e.g. drop deformable scenery), and where to make quick wins (e.g. support for more input devices).
Okay, so I don't have a brilliant track record in game development, but I *do* have a very good track record in IT projects, and to some extent it's the same principle. The best visionaries are those that have grown into the role. (They're also those that will acknowledge their weaknesses and get input early on in the areas they don't know).