I have never built a deck for this before, and if anyone can tell me the best percentages of Friends, Dark, World, Equipment, Magic, etc. for the ultimate balanced deck, it would be good.

Knuckles Eki said:

There isn't an ultimate percentage. My deck for GenCon ran something like 8 friends in it, and was top 2. The other in the top ran about twice that.

a good world rush or even aggro does well in the 40-42 card range. i find at max like 21 freinds then the rest what you need to win. but really depends on the deck idea.