That is indeed the traditional view, but English has changed beyond that. Most if not all modern major dictionaries do list the adjective sense. Quoting Oxford here:
The use of fun as an adjective meaning ‘enjoyable,’ as in we had a fun evening, is now established in informal use. The comparative and superlative forms funner and funnest are sometimes used but should be restricted to very informal contexts.
We do accept "funny" here as well, though. Besides, in "The party was fun", the word "fun" is a an adjective - predicative through the copula "was".
I hear it as "Det va e rolig fest.", is that the standard in casual speech?
Maybe in some dialects, but I think I hear at least a trace of the n in en in most dialects. The r in var is rarely heard though.
Ok I am having the hardest time figuring out how swedish gets by as a language without a distinction between funny and fun. Det var en rolig fest "It was a fun part/It was a funny party" This game is so much fun! (addicting) "Denna spelen är så rolig" ? The game is not at all funny, but it is so much fun to play, how do people not get confused?
Shouldn't "It was an amusing party!" be OK as a translation? I'm just trying to better understand what's the general meaning (and use) of "rolig".
Don't know if it should be an accepted answer, but amusing is more like underhållande so the suggested translation is better.
kul works too, makes no difference in this case.
rolig means both funny and fun and then some.