How exactly drain work ?

[Eressil3]

I never took drain in MP because I love magic.

But I'm starting to consider it.

1- is there a reason to not take Drain 2 over Drain 1 ?
2- does it have negative side effect like reducing for instance the number of creatures summoned/reanimated ?
3- does the enemy gain MR under your dominion ?
4- is there something undocumented about drain ?
5- why do/don't you like drain ?

[Endoperez]

1) Very little.
2) Nothing that drastic. Higher Drain makes spellcasting more fatiguing.
3) Yes.
4) Can't say for sure. The exact effect it has on spellcasting manual might be undocumented. I don't remember seeing any details.
5) Certain nations are immune to Drain research penalty, and others have insanely cheap researchers that benefit very well from Magic. For those, the choice is always easy. Some nations don't need magic much, so they can survive with Drain. Niefelheim, perhaps, with access to good infantry and good SCs in Niefel Jarls.

[MaxWilson]

1. Only if you're planning on using lots of resistable battle magic (astral or death).

5. Psychologically, I want my mages to be as powerful as possible so I frown at drain. Realistically, magic/drain affect both sides equally, and half of the time I'm fighting outside of my own dominion anyway so I should take it. Drain for me is kind of like Death scales. Rationally, it wouldn't hurt me any to take it (especially if I can forge research boosters) but I'd rather take Magic/Growth instead because I have more fun.

(BTW, I think the recent changes to Production scales are awesome. For the first time ever, I'm wishing I had enough spare points to take Prod-1 or Prod-2.)

-Max