Can you use Platnium coins in the place of Gold?

[Sims]

Sounds like a given, I'm sure, but for others it may not be true.

Say I had a spell that required 100 gold. But all I had were platnium pieces. Would I be able to use the Platnium currency instead?

[Gnoman]

It depends. As a spell component, usually it's rather specific, so if a spell specifies "100 gp" as a material component, probably not. If, however, you DM is allowing you to just pay the price for material components (such as "diamond dust worth at least 100 gp") than you probably could be able to.

As currency, that depends solely on your DM. Some use all 4 coins universally, while others require you to break them down into gold or even silver for certain shops.

[KillianHawkeye]

If you're talking about "<X material> worth N gold pieces," then you should be able to buy that material with N/10 platinum pieces because the value is the same.