GemCraft – Chasing Shadows Guide

Optimal skills distribution for GemCraft - Chasing Shadows

Optimal skills distribution

Overview

Optimal skills tables, Skills allocator notebook for a custom setup, a full explanation of the theory of skills optimization, some discussion on the Amplifiers skill and more.

Introduction

This guide will talk about the optimal skills distribution of uncapped skills for high level players.
The capped skills are either useless or should be maximized around the time the uncapped ones get to 30-50.

The guide will deal in SP, which is the number of skill points you leave free to be allocated in the uncapped skills, after you’ve filled your capped skills and left enough for initial mana.

Some prerequisites for it to be useful are:

  • Having explored most of the game fields, to get all the useful skills (there is a section below for the non MP players on flash sites, who cannot obtain certain skills), this wiki page[gemcraft.wikia.com] will help collecting them all
  • Being level high enough to have capped the basic skills, have enough SP spare for mana and enough to put on uncapped skills, I’d say at the very least WL 2k
  • Using the optimal endgame gems: you don’t need to follow the Extreme End Game Guide 1.1 to the letter, but you must use OBR and YBR gems
  • Having read the Extreme End Game Guide 1.1 glossary, as I use that terminology here.

If you prefer having a general hint rather than a list of precise numbers, there is a skill hierarchy and we can rank the skills from higher to lower optimal level:
TColors≳BBound>>Leech>>Traps>>CritHit>Reson
The Amps skill is difficult to place, but should generally be around the same level as Resonance.

Next section will talk about the theory behind the optimal skill distribution, if you just want optimal numbers head to the “Skills table” section.

Skills distribution theory

Warning: math ahead

First of all we need to figure out how many skill points every skill level costs, it’s pretty straightforward, to buy up to the Nth level of a skill you need:

SP(N) = N*(N + 1)/2

Then we need to understand which skills are important to raise, given a defined playstyle:
True Colors, BloodBound, Leech, Traps, Critical Hit, Amplifiers and Resonance are the obvious choices, as we use OBR, YBR, SlowBR gems and O, Y amps.

Chain Hit and Slowing are not needed, you may want to dump some points in them at mid level,
but at high level the BBound modifier gets you all the CH/Slow you could ever want.

To make things easier we won’t consider amplifiers for now, so we just have to deal with triple gems and know which part of TC to apply.

At this point we need to see what effect those skills have on the game stats, so let

{tc, b, l, t, c, r}

be the level of every skill (name got from their initial) and ‘ta’ be the bonus granted by your talismans.

The raw bonuses look like:

TCs(tc) = 1/2 (1 + (1/10)*(tc + ta)/3) TCd(tc) = (1.2 + (1/10)*(tc + ta)/3) Leech(l) = (1 + 4/100*(l + ta))*(1 + 5/100*(l + ta)/3) Bbound(b) = (1 + 4/100*(b + ta))*(1 + 5/100*(b + ta)/3) Crit(c) = (1 + 4/100*(c + ta))*(1 + 5/100*(c + ta)/3) Traps(t) = (1.8 + 5/100 (t + ta)) Reson(r) = (1 + 4.5/100 (r + ta))

where TCs is the skill part of TC and TCd is the damage part of TC, both for triples.

I assume your gems are at the speedcap (all the decent gems get to the speed cap before g40) and rangecap, so we don’t bother with those parts.

Now let’s consider what we want to maximize, we’ll divide the problem in 3 parts:

Understanding managems

The power of a managem is its displayed leech, which is given by:

(1+BB*hitLevel)*leech -> high level -> BB*hitLevel*leech

So the merit figure for a managem is bb*leech, as there is no way to influence the hitLevel via skills.

We now figure out how the skills influence this product, we get:

leech_after_skills = TCs(tc)*Leech(l)*base_leech bbound_after_skills = TCs(tc)*Bbound(b)*base_bbound being in trap -> Traps(t)

Putting it together, we get that the power of a managem is:

TCs(tc)^2 *Bbound(b)*Leech(l)*Traps(t)*base_gem_manapower

So finally we know what is the quantity we need to optimize for mana gaining:

M(tc, b, l, t) = TCs(tc)^2 *Bbound(b)*Leech(l)*Traps(t)

if we were to maximize this with respect to tc,b,l,t over the constraint of a maximum expendable SP, we’d get the best setup for mana farming.

But then we need to kill monsters, too, so let’s

Understanding killgems

The power of a killgem is its displayed max damage times its displayed crit (times 0.8 times 0.5, which are constants so we never care about those), which is given by:

(1+BB*hitLevel)*damage*(1+BB*hitLevel)*crit -> high level -> BB^2 *hitLevel^2 *damage*crit

So the merit figure for a killgem is bbound^2 *damage*crit, as there is no way to influence the hitLevel via skills.

We now figure out how the skills influence this product, we get:

damage_after_skills = TCd(tc)*Reson(r)*base_damage crit_after_skills = TCs(tc)*Crit(c)*base_crit bbound_after_skills = TCs(tc)*Bbound(b)*base_bbound being in tower -> no extra bonus

Putting it together, we get that the power of a killgem is:

TCd(tc)*TCs(tc)^3 *Bbound(b)^2 *Crit(c)*Reson(r)*base_gem_killpower

So finally we know what is the quantity we need to optimize for killing:

K(tc, b, c, r) = TCd(tc)*TCs(tc)^3 *Bbound(b)^2 *Crit(c)*Reson(r)

if we were to maximize this with respect to tc,b,c,r over the constraint of a maximum expendable SP, we’d get the best setup for killing monsters.

Sadly, we can’t maximize just M or K, we need to keep a balance between the two and the next section will find the best balance with some reasonable assumptions.

Joining M and K together

The basic idea is that the final goal is building the best killgem possible and mana is just needed to build bigger managems to get more mana to finally build a killgem.

So, let’s assume a base managem power is P, with skills it becomes M*P, which allows us to gather M times more mana as before, allowing us to make a killgem M times more costly.
But we know how much damage a killgem gains when we put more mana in it, it’s given by the growth equation:

Killpower_increment = M^gk

where gk is the growth of the combine method we use on the killgem.

Luckily finding combine growths is exactly what gemforce does, so we have all the possible combines and their growths and we can estimate this, the skill allocator uses the growth of the 16c for killgems:

gk = 1.41

but the exact growth doesn’t matter much in the final result, so you are good even if you use ‘U’ or 719k combine, or you can give the growth of your favorite method to the allocator notebook for finetuning.

Now, adding in the benefit provided from K, we have:

First_order_Global_Power(tc,b,l,t,c,r) = M(tc,b,l,t)^gk * K(tc,b,c,r)

which seems the right function to aim to maximize…

But wait, there’s more!

If we can get more mana from skills, we can use that mana to make better managems, to gather even more mana, to build even better killgems.

As before, if we now gather M times more mana, we can build managems M times more costly and we get:

Manapower_increment = M^gm -> gm = 0.625

where the value of the growth is again 16c managems.

At this point, if P was the skillless mana and M*P the skill mana, we can get more upgrading the managem, to reach:

New_manapower = M^gm * Old_manapower = M^gm * M * P = M^(1+gm) * P

But now, we have a better managem, we get more mana, we can upgrade again.

New_manapower = M^(1+gm)^gm * Old_manapower = M^(1+gm+gm^2) * P

And again, and again, and again.
In the high level gems approximation we can take the limit, which yields:

Final_manapower_increment = M^(1/(1-gm))

Now, with this new mana increment we build a killgem, putting it together with the previous killgem formula we have:

Global_Power(tc,b,l,t,c,r) = M(tc,b,l,t)^(gk/(1-gm)) * K(tc,b,c,r)

this is the formula we need to maximize to have the best skill setup, and that’s exactly what the notebook does.

The number gk/(1-gm) tells you how much you need to prioritize mana skills over kill skills (luckily TC and BB overlap) and it’s around 4, which means that mana skills are much more important than kill skills.

From maximizing this function it can be seen that the skills always have a certain order from best to worst (which corresponds to the power they have in GP), which gives the skill hierarchy I wrote in the introduction.

Skill allocator notebook

To actually do the computations needed I wrote a Mathematica notebook, which gets your SP number (and some minor parameters, if you like, but the defaults are mostly fine) and computes the best skills setup with that SP number.

It’s the program that built the table in the next section.

You can retrieve it from the skill-allocator repository[github.com]: Notebook URL[github.com]

Skill table

Here follows a table of optimal distribution for multiples of 5k skill points.
If you have a number somewhere in between two points just interpolate in some way.
For a perfectly tailored distribution use the Notebook in the previous section.

For the latest version, up to 400k SP (and a better table rendering) look at the version in the repo[github.com]

Skill Points
Global Power
True Colors
BloodBound
Leech
Traps
Critical Hit
Resonance
10000
3.635e17
84
81
60
40
24
17
15000
3.082e19
102
99
75
49
30
22
20000
8.854e20
117
114
87
59
36
23
25000
1.349e22
132
126
99
64
39
28
30000
1.342e23
141
141
108
69
48
31
35000
9.881e23
153
147
120
78
51
36
40000
5.768e24
165
162
120
84
54
39
45000
2.824e25
174
168
135
89
57
38
50000
1.187e26
183
177
141
95
60
44
55000
4.443e26
192
186
144
101
66
50
60000
1.502e27
201
195
153
104
66
47
65000
4.645e27
207
201
162
110
72
49
70000
1.326e28
213
216
162
114
72
52
75000
3.602e28
222
216
174
118
75
58
80000
9.150e28
231
225
177
120
78
57
85000
2.214e29
234
234
180
125
87
63
90000
5.100e29
243
243
183
128
87
59
95000
1.136e30
252
243
195
130
84
67
100000
2.441e30
258
249
198
134
93
68
105000
5.043e30
264
258
204
134
93
67
110000
1.011e31
270
264
204
145
96
67
115000
1.968e31
276
267
213
143
102
72
120000
3.747e31
282
276
213
149
102
72
125000
6.977e31
285
282
222
150
102
77
130000
1.268e32
288
288
228
156
105
75
135000
2.243e32
291
294
231
162
111
76
140000
3.932e32
303
297
234
162
108
78
145000
6.721e32
312
300
240
162
108
77
150000
1.139e33
312
306
246
166
114
82
155000
1.889e33
318
312
249
168
114
84
160000
3.079e33
318
321
252
171
120
86
165000
4.965e33
330
318
258
172
123
86
170000
7.875e33
336
324
258
177
121
91
175000
1.245e34
336
333
261
183
123
90
180000
1.935e34
339
339
267
182
129
88
185000
2.970e34
348
336
273
189
129
88
190000
4.521e34
348
345
279
189
129
91
195000
6.772e34
354
351
273
198
135
90
200000
1.013e35
357
357
282
196
132
91
205000
1.490e35
363
363
279
197
141
92
210000
2.189e35
366
360
291
202
138
102
215000
3.189e35
372
369
291
201
138
99
220000
4.576e35
375
378
291
200
141
102
225000
6.559e35
384
375
297
206
141
99
230000
9.284e35
387
381
300
206
144
101
235000
1.312e36
384
384
309
211
150
105
240000
1.826e36
390
393
303
210
153
112
245000
2.560e36
396
390
312
220
150
106
250000
3.532e36
405
393
315
217
150
105
255000
4.862e36
402
402
315
223
156
109
260000
6.643e36
408
405
321
225
150
108
265000
8.987e36
414
408
318
228
153
118
270000
1.213e37
417
417
324
222
157
108
275000
1.642e37
420
414
333
228
159
111
280000
2.192e37
429
414
333
228
165
113
285000
2.912e37
429
420
336
230
171
113
290000
3.879e37
432
429
336
236
162
113
295000
5.122e37
435
432
342
235
165
114
300000
6.721e37
438
435
345
236
171
115

Amplifier skill

Including the Amplifiers skill in the standard computation is very difficult, because the improvements it brings depend on the ratio of manacost of a gem on its amps.

Conversely, the optimal gem/amps cost ratio depends massively on the amps skill, which makes this problem impossible to solve exactly (unless someone with a huge amount of free time wants to integrate gemforce and the skill allocator together).

Gemforce, though, accepts the value of the amp skill to get the best ratio and can give us some constraints:
even at very high amps skill (>500) the amps still stay below half of the value of the mana/killgem, which helps us estimating the maximum power we can get from the amps skill.

At present day values and levels I value the Amplifiers skill power more or less as Resonance, but I cannot show the math, as it’s a mess (will do, if asked).

For players without Magician Pouch (flash sites only)

Players without Magician Pouch suffer the fact they have no Bbound skill and that they don’t have black gems in every stage.

When black gems are available, the best strategy is the same as the normal one (OBR and YBR), with the skill distribution obtained by forcing BB skill to be 0.

Follows the table for fields with the black gem (better version at the repo[github.com]):

Skill Points
Global Power
True Colors
Leech
Traps
Critical Hit
Resonance
5000
1.259e12
72
54
34
18
15
10000
1.783e14
102
75
48
30
22
15000
4.477e15
123
93
61
39
25
20000
5.093e16
141
108
72
45
29
25000
3.626e17
156
120
84
51
34
30000
1.912e18
171
132
88
57
43

If the field you are playing has no black gems you’ll need to use white (or no bound at all).
In this case the optimal distribution changes markedly, as you don’t have the TC bonus for bloodbound (poolbound benefits from TC, but the scaling is too small to make a difference)

In this case the formulas described in the theoretical section change to:

Mn(tc, l, t) = TCs(tc)*Leech(l)*Traps(t) Kn(tc, c, r) = TCd(tc)*TCs(tc)*Crit(c)*Reson(r) GPn(tc, l, t, c, r) = Mn(tc, l, t)^(gy/(1 – go)) * Kn(tc, c, r)

where ‘go’ and ‘gy’ are the growth of the bound-less gems.
Be careful that this is valid for gems at the speed cap, if you cannot reach the speed cap yet you should keep the mana skills higher than this.

Here follows a table for fields with no black gem (better version at the repo[github.com]):

Skill Points
Global Power
True Colors
Leech
Traps
Critical Hit
Resonance
5000
1.086e6
60
57
37
33
22
10000
1.418e7
81
81
53
51
34
15000
7.726e7
99
99
67
60
44
20000
2.778e8
117
114
75
69
50
25000
7.836e8
129
129
85
78
54
30000
1.880e9
141
141
93
87
59

Credits

12345ieee – Author of the guide
Suuper – Help with math

If this project helped you and you wish to help by contributing, please contact me, leaving a
new Github issue[github.com] or opening a new pull request.
You can also help by donating some money for my time:
Donate to this project using Paypal[www.paypal.com]

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