With how much a lot of multiplayer wars come down to people pressing their countries to breaking point you'd be surprised how much of an impact anything that can effect economy hurts too such as Slander Merchants.ДЄdministrative, Defensive, and Espionage ideas together would provide an amazing -0.4 corruption reduction with 3 policies in total, which is enough to halve the maximum corruption from territories. Oh speaking of multiplayer the ability to quickly build up spy networks and do things like lift Fog of War in lategame wars is actually really strong and in it's own right kinda makes Espionage worth considering once Infiltrate Administration shows up. It's just Espionage tends to get crowded out a bit because it's a Diplomatic group. In multiplayer Diplomatic and Influence are bad idea groups. It's just the idea group focuses on more niche aspects of the game instead of 'Me stack Discipline me roll over and blob'. There's 20% cav combat for cav nations -1% tradition decay 33% manpower Fort Defense 25% more merc and -15% merc maint Corruption reductions and if you really want to meme you can stack Rebel Support to +125% with Policies. +50% Rebel Support Efficiency is alright but it's not something you use too often I find.ДЄs far as Diplomatic Idea Group policies go Espionage is really good. 0.1 Yearly Corruption is alright and helps out if you're super-blobbing. The ability to fabricate claims for subjects is actually pretty big especially if playing a subject-focused game.Д®mbargoes and Pirates are *nice* bonuses. However spies being discovered isn't exactly great for diplomacy like AE isn't great for it. 20% AE impact is a nice bonus especially in the HRE. +33% Spy Detection is pretty nice seeing as the AI has a hate-on for the player and spams them with spies and spy actions lategame. +1 Diplomat is alright considering you want to be using them for spying I'd actually say the best idea in the group is the first one, which gives -10% advisor costs and +50% network speed, drastically increaseing the speed you build networks while also saving on Advisors which is always nice. It has a load of useful bonuses but the situation where all of them are useful is quite rare. When you're blobbing you have little~no need for diplomacy just making your country run and your solders kill.Д®spionage is, in a word situational. Admin groups help your country run better and more efficiently. First and foremost it's a Diplomatic group which, to be honest, are in general the least useful.

Espionage ideas eu4