Its 40 more exp to the next level. Supposing...

Level 1 = 40 exp to level 2.
Level 2 = 80 exp to level 3.
Level 3 = 120 exp to level 4.
Level 4 = 160 exp to level 5.

And so on. Now, lets assume 40 exp for 20 energy (average between missions and NPC's). So you'd need 20 engineers, or about 10 rank points worth. I revise my earlier energy / engineer amount. I was going for 25 energy for 55 exp for the weekly's which are generally the lowest energy cost missions that consistently come up. That would require about 13 rank points in engineers, or 3 prisoners + 1 rank up worth of points. The other missions for higher up's take 100+ energy, and the top missions take over 200+ a click, so the 25 energy one gives you much more control of exp and maxing energy usage instead of wasting it. Plus there will always be new weekly missions, so you won't run out of 25 energy for 55 exp missions.

Wait... where was it ever mentionned there was such a nerf? I do kinda feel like I get fewer, but the updates' board does not mention anything like that.

That said, auto-ranking/power leveling is, in theory, impossible to keep doing indefinitely, because yes, you need 40xp more than the last level, every time and no, you can't really get a 4:1 return consistently afaik. You can certainly rank up a lot, but you will need to stick to engineers to keep ranking and you will eventually run out of neurals or missions or you will get a bunch of bad xp:energy ratio NPCs and it will stop.

And no Dan shouldn't do anything against auto-ranking or power leveling because all it gets you is a nice number, planet slots and a strong crew for raids... which doesn't amount to much to be honest.

On the flip side, nerfing prisonners or any artifact drop with permanent increases WILL favor ranking faster.

You can't rank faster if you're only able to put 5 points into engineers every level or if you split points into engineers and tactical officers compared to 10 - 15 points into engineers you'd get from the combination of engineers AND rescued prisoners.

I said the nerf in prisoners cuz myself and quite a few of my legion mates haven't found rescued prisoners in a few days and we have incomes of multi-thousand AP per hour.

just because you're not getting them for a few days doesn't mean they're not there... within 200K AP i've found 3 rescued prisoners recently..

......why is it people only tend to complain when the random number generator fails for them?

you're BOUND to have dry spells... even with totally random events, you'll see dry spells.... those dry spells come randomly too!!! just like success streaks!!

You're talking to the guy who went for almost 3 months without ONE SINGLE Octofari Leviathan even though I hadn't completed the mission. It took me another month and half to get all 4.

i went about that long without seeing a single Mass Storage Pod... i had started scrapping crimson obelisks and using up other artifacts just to have room for my mineral and arti pulls

it's all the fault of the random number generator..... other people were getting MSPs but i wasn't...
just like right now, i'm having problems getting android helmsmen... i've been stuck at 67 for a few weeks now

Leviathans though.... those weren't very common anyway... even for being an uncommon, they were an unusually rare sight... i'm only glad i did the kalvium asteroid mission when it was a timed mission, which meant Embattled Retreat stayed active on my list for months, long before i was able to start doing it... so i had many many months to get my 4 leviathans

You're oversimplifying it; production isn't just about number of planets but also about the quality, which is the advantage of auto-ranking fighting NPCs: you get a lot more Terraforming Devices and other planet increasers, so even if you have the same amount of planets you might have much larger production.

You would need tactical officers to have enough attack power to blow through the hated Flamehawks once you pass level 350. These guys are meant to slow down power levelers, and you can't kill them as fast as the other NPC's if you have low attack power by not investing in tactical officers. So your NPC'ing would slow down quite a bit.

Um, was that a reply to me? It doesn't at all apply to what I said. I'll try to simplify:

You said: They won't have more production because they can't afford to take more planets.
Which implies (or, your assumption is): You need more planets for more production.

I replied: Your assumption is false, you do not need more planets for more production.
And counter-argued: Fighting NPCs lets you increase individual planets that you already own.

What you're misunderstanding:
You think the point of auto-ranking is to get more levels. You think this doesn't work because in order to do that you're putting all of your rank points into Engineers, and thus your attack can't keep up, effectively neutralizing your fighting ability against slow-rankers of your own level and higher level NPCs, and thus not letting you kill enough NPCs to keep getting these planet increasers.

The reality: The point of auto-ranking is to see as many NPCs as you want, so you constantly get good drops to constantly improve your planets. True, the ranks themselves don't make you stronger, they just give you more energy, but they let you keep hunting. You do not need to put all your rank points into Engineers, only the ones you get from leveling. You can put all your other rank points (mostly from Rescued Prisoners) into Tactical Officers, so your attack and keep increasing. I've been doing this, killing well over 1000 NPCs a day, for a couple weeks, and it works plenty well. I didn't get as many good drops as I would've liked (because of the temporary change in rarity) but I did get plenty, so my average production per planet is growing very significant. If you are careful and know what you're doing, this strategy can work very well, as it has for me. Far from NPCs getting too tough, I've seen the amount of hits per NPC start to decrease (I think a month or so ago I got down to killing Dark Runners in 2 hits almost every time).