The script is stuffed with manipulations, lies, surprises and dumb characters so it's nearly one laugh guaranteed with every lines! To keep your pleasure, i wouldn't tell more, above all it is very complicated to resume!
I had the pleasure to see 3 versions of this story: one with "Sly" Stallone, another with Bernard Tapie (ex-president of the biggest football club in France, ex-Minister, ex-prisoner and now actor) and this one with De Funès.This latter, even being the oldest stays the best and for a long time, I think!
When people say De Funès knows only to make faces, I would recommend watching "Oscar" wide eyes open! Louis excels with his tone, his energy and his reactions. If he plays again and always a Machiavellian bad guy, for me, he shows a lot of humanity and a big heart!
That's the only problem with De Funes: as his movies built my childhood, I confused his real kindness with his characters: in other words, he makes me happy so he inspired me. But as his embodies bad guys, vile boss and hypocritical, I copy that and never have his success. Everybody was taken my words for real!
De Funès should have won an Oscar for this "Oscar"!