Look, the IRC logs. (Edited so mage levels/nations etc are obfuscated. Do not want to give your enemies even more information).
[21:18] [RagnarokX_] can someone help me with dispel spell ?
[21:18] [Soyweiser] whappupwithit?
[21:19] [RagnarokX_] i wanna know how much i need to spend
[21:19] [RagnarokX_] i have an astral X mage and want to dispel a spell
[21:20] [Soyweiser] Has the astral spell been put up during the early game when there where still slots left?
[21:20] [Soyweiser] Then it is probably min level boosted (so no bonus gems)
[21:20] [RagnarokX_] it was put up a couple turns ago
[21:20] [Soyweiser] Does the enemy nation have high astral on his pretender?
[21:21] [RagnarokX_] i dont know their pretenders magic
[21:21] [Soyweiser] "a couple of turns ago" Dude.. this provides me with zero information.
[21:21] [Soyweiser] I don't know which turn your game is in.
[21:21] [RagnarokX_] this turn is [removed]
[21:21] [RagnarokX_] so maybe turn [removed]
[21:21] [Soyweiser] Where there still slots left?
[21:21] [Soyweiser] global slots?
[21:21] [RagnarokX_] there are free global slots
[21:21] [RagnarokX_] stellar focus
[21:22] [Soyweiser] (You should really learn to provide a little bit better information btw, this I shouldn't have had to ask)
[21:22] [Soyweiser] s6 on your pretender I assume?
[21:22] [RagnarokX_] no, I have a sX mage
[21:22] [Soyweiser] only natural magic levels boost dispels
[21:22] [Soyweiser] So boosters don't help
[21:23] [RagnarokX_] he is Sx unboosted
[21:23] [Soyweiser] Right, dispell is s3 right?
[21:23] [RagnarokX_] yes
[21:23] [RagnarokX_] its stock, s3 and 30 gems
[21:23] [Soyweiser] So that gives you 10 bonus gems right there for the dispel. (Personally I would try to dispell GoH first)
[21:23] [Soyweiser] So stellar focus is s5 right?
[21:24] [Soyweiser] Assuming he has a natural or item boosted caster for that (and not a natural lvl 6 caster) it isn't boosted with any additional gems.
[21:24] [RagnarokX_] yep
[21:24] [RagnarokX_] sx
[21:24] [Soyweiser] So a min level dispell should work
[21:24] [RagnarokX_] how much should i spend to make sure i dont lose out ?
[21:24] [Soyweiser] With your bonus of +(x-3) times 5 + 1d6 (open ended) You should be able to beat his +0 + 1d6.
[21:24] [Soyweiser] I would throw zero boosted dispell at it first personally.
[21:25] [RagnarokX_] ok
[21:25] [RagnarokX_] i have never dispelled yet
[21:25] [Soyweiser] With zero taken slots, it probably has not been boosted.
[21:25] [RagnarokX_] will he see who tried dispelling it, i.e. reveal myself ?
[21:25] [Soyweiser] Yeah, all this information was on the wiki
[21:25] [Soyweiser] nope.
[21:25] [RagnarokX_] ok
[21:25] [Soyweiser] And failed dispells don't even show
[21:25] [Soyweiser] to other players at least
[21:26] [RagnarokX_] could i try to cast SF myself instead of dispelling first ?
[21:26] [RagnarokX_] overpowering his ?
[21:27] [Soyweiser] Well, then you need to put in some additional gems, but there is a higher payoff (dispelling it first 30sgems, + casting it, (cost of SF + boost)) vs casting SF + boost.
[21:27] [Soyweiser] So yeah, overpower that ****.
[21:27] [Soyweiser] Put some more gems in there btw. He can pull the same dispell back at you. He probably has natural s5 mages
[21:28] [RagnarokX_] how much would you put into it ?
[21:28] [Soyweiser] I don't know.
[21:28] [RagnarokX_] heh
[21:28] [Soyweiser] Depends on if I think I will stick with it.
[21:28] [Soyweiser] In this case I would perhaps put a few more in it. Just to deny it to Rlyeh
[21:29] [Soyweiser] You can never have enough astral gems
[21:30] [Soyweiser] look, the SF costs 30 right? so that is a ROI of 6 turns right there. Put 50 more in and it is a ROI of 16. Wayyy to much.
[21:30] [Soyweiser] So boost it with 20 additional gems, still a ROI of 10 turns, but it will give R'lyeh some headackes if he tries a min dispell with his s5 mage to get it back.
[21:31] [RagnarokX_] ok
[21:31] [Soyweiser] (And you really should try to determine which type of god and paths he has. If he used a expansion pretender he probably doesn't have s9. But if his sacreds have twist fate he has).
[21:32] [RagnarokX_] would equipment like spell focus or something aid in overpowering and or making my SF more resilient ?
[21:33] [Soyweiser] iirc nope
[21:33] [RagnarokX_] thanks
[Naglfar] How about just directing him to page 87 & 88 in the manual.