Spellpower calculation?

[thalen]

So, I'm running an arcane blade, and I am completely flummoxed by spellpower. Specifically, I simply don't understand how it is calculated.

When I am adding stats in the level-up screen, it says that if I add a point of magic, it will give me a point of spellpower. Additionally, I'm supposed to get 21% of my cunning (which is currently quite low, but still should be a couple of points) as spellpower from the talent Arcane Cunning, which I have at level 1. I don't know if anything aside from the magic stat and my cunning add to spellpower, or, more to the point, subtract from spellpower. But I have a magic attribute of 45 (which should net me 45 spellpower, or at the very least 35 if it is counting from the base (10) instead of from 0) and a cunning of 25 (which should add 5 points), I am having a lot of trouble understanding why my spellpower should be 35.

[nate]

Things like spellpower are designed to give diminishing returns. I can't remember the exact thresholds, but, say, your first 5 points give you one point each, while your second 5 points only give you a half point each-- in that case, 9 spellpower gets translated to 7 spellpower.

I looked on the wiki for an explanation, didn't find one, but the best explanation is in the in-game tutorial anyways.

[phantomglider]

Every 20 points, it takes an additional +1 raw spellpower to get +1 effective spellpower.

So, for example, you have +45 Spellpower from Magic, and +5 Spellpower from Cunning. This get to 20 Spellpower with another +30 raw which becomes 15 effective - 35 in all. If you get another 30 raw spellpower, for a total of 80 raw spellpower, you will be at 20+(40/2)+(20/3)=46 or 47 spellpower.

[Roghain]

Okay, now you lost me. From what you said, I reckoned it would be:

20 + (20/2) + (20/3) + (20/4)

And so forth? But I seem to miss something, with the second factor to be 40 in stead of 20. Where am I going wrong?

Or is it for every 20 effective it takes 20 extra raw.

[twas Brillig]

The Character sheet page of the wiki gives an explanation. ToME's diminishing returns are probably great for balance, but they can make scaling really hard to figure out. 1.3 has a small usability boost in that equipment will tell you both the raw boost value, and the effective boost from equipment.

Here's the relevant text:

It costs more to increase scores that are in higher tiers. For each tier, here's the cost of increasing your score by one:

• Tier 1: 1 point, from 0 to 20
• Tier 2: 2 points, from 20 to 40
• Tier 3: 3 points, from 40 to 60
• Tier 4: 4 points, from 60 to 80
• Tier 5: 5 points, from 80 to 100

So, assuming you don't have any equipment that boosts spellpower, 45 spellpower + (0.21)*25 cunning = ~50 base.
0-20 points -> 20
20-40 points -> 20+10 = 30
40-50 points -> 30 + 10/3 = ...33, apparently.

[grayswandir]

Or is it for every 20 effective it takes 20 extra raw.

This.

So say you have 100 base points:
You get 20 at full rate: 80 base, 20 effective
You get the next 40 at half rate: 40 base, 40 effective
The next 60 at 1/3 rate, but we run out: 53 effective

So the breakpoints are:
20 -> 20
60 -> 40
120 -> 60
200 -> 80
300 -> 100

[Roghain]

Cheers. That helps.