[Tom_Scudder]

Not too severely - 15 gems per clam instead of 10. The bigger obstacle is that you now need 2 water 1 nature to make one, which means you'd need to be pretty lucky to have more than one forger out of 20 starspawns (1/32 chance of getting the 2 ?s to line up just right) - although you can add water bracelets, that means you can't start clamming until you hit Con 6. Or I guess if your pretender has a high water, he could forge a couple water robes at con 4, but that's still a lot of extra fuss for a clamming strategy.

Jotun Skrattis have pretty good odds of being clam-forgers under CB (1/4) - among independents, amber clan mages are all clam-forgers, and jade amazon sorceresses have a pretty good shot at it. Atlantis, Caelum and Tien Chi (I think) also have decent shots at clam-forgers among their recruitable mages.