I only get the exp increase abilities IF I am not offered any levelups that I want for the particular hero.

harpo

I was also taking the xp booster traits due to behavior training from Beta.

It was only once I took a look at the math did I realize I was probably shooting myself in the foot.

I'm a big fan of making decisions exciting, but there are such limited avenues for "new" levelup traits. What if I took those 4 traits and turned them into summons? A level 1 shadow warg, level 4 bear, level 5 demon as substitutes for potential 1, 2 & 3. Those spells already exists as champion useable abilities in the code. And none of that would be overpowered later in the game. Hm... what to do with Knowledge (which requires Path of the Mage as a prereq)?

I use them sparingly- only for governor heroes to get them to lvl 4.

Some xp boosts give more xp to the entire stack and that can make a big difference.

If XP leveling progress is geometric and XP bonuses are linear, they are quite worthless IMHO

Whith all respects, I think your figures are mistaken. That's what I've Collected

Level --> Additional XP --> Total XP

01 --> 010 --> 0,010
02 --> 022 --> 0,032
03 --> 037 --> 0,069
04 --> 054 --> 0,123
05 --> 074 --> 0,197
06 --> 097 --> 0,294
07 --> 122 --> 0,416
08 --> 150 --> 0,566
09 --> 181 --> 0,747
...
14 --> 381 --> aprox 2,222
15 --> 429 --> aprox 2,651
16 --> 481 --> aprox 3,132

The quantity needed to reach next level grows with each iteration, but each time it grows at a slower pace. The most impressing jumps are at the first levels while te later levels are not so different in comparison.

Using the data provided by OliverFA_306 (thank you) and Ulysses_31's delta formula (again, excellent work)...

we can see that total xp at a given level is estimated by the summation of all previous delta xp i.e.

the summation from n=0 to n=(level desired to know total xp) of 1.4*x*x+8*x

which can be verified to follow the total xp progression (within a small error) using the free online summation calculator on 

http://mikescosmos.com/Sum.php 

So let's make a bigger xp table based on this pseudoformula:

level              estimated total xp (from formula)              actual total xp (from OliverFA_306)

1                         9                                                                 10

2                        31                                                                32

3                        68                                                                69

4                       122

5                       197

6                       295

7                       420                                                              416

8                       574                                                              566

9                       759                                                              747

10                     979

11                    1236

12                    1534

13                    1875

14                    2261                                                            2222

15                    2696                                                            2651

16                    3182                                                            3132

17                    3723

18                    4320

19                    4978

20                    5698

21                    6483

22                    7337

23                    8261

24                    9260

25                   10335

26                   11489

27                   12726

28                   14047

29                   15457

30                   16957

So let's take a look at bonus xp effects (assumed from level 1, the start of xp gain for simplicity):

base xp                 15% bonus xp           35% bonus xp          60% bonus xp           85% bonus xp         110% bonus xp

no modifier             Potential 1               Potential 1+2            Potential 1+2+3       Pot1+2+3+ Know     P1,2,3+Kn+Brill

9      level 1               10 level 1                12  level 1                   14 level 1               17 level 1                     19 level 1

31    level 2               37 level 2                42 level 2                    50 level 2               57 level 2                     65 level 2

68    level 3               78 level 3                92 level 3                   109 level 3              126 level 4                143  level 4 

122  level 4               ...                           ...                              195 level 4              226 level 5                  256 level 5

197  level 5                                                                              315 level 6              ...                              414 level 6

295  level 6                                                                              472 level 7              546 level 7                  620 level 8 

420  level 7                                            567 level 7                  ...                           777 level 9                  882 level 9

574  level 8                                            770 level 9                                               1062 level 10               1205 level 10

759  level 9                                           1025 level 10              1214 level 10           ...                               1594 level 12  

979  level 10                                          ...                              1566 level 12            1811 level 12              2056 level 13

1236 level 11                                                                          1978 level 13           2287 level 14               2596 level 14

1534 level 12                                                                           ...                           2838 level 15              3221 level 16 

1875 level 13                                                                                                         ...                              3938 level 17

2261 level 14                                                                                                        4183 level 17               4748 level 18

2696 level 15                                                                         4314 level 17            4988 level 19               5662 level 19

3182 level 16                                         4296 level 17             5091 level 19            5887 level 20             6682 level 21  

3723 level 17          4281 level 17            5026 level 19             5957 level 20             ...                            7818 level 22

4320 level 18          4968 level 18            5832 level 20             ...                                                            9072 level 23

4978 level 19          5725 level 20            ...                                                            9209 level 23            10454 level 24

5698 level 20          6553 level 21            7693 level 22            9117 level 23            10541 level 25          11966 level 26  

level Gain:

 zero levels              one level                 two levels                  three levels                five levels                 six levels

level up picks used for bonus xp gain:

zero                         one                        two                            three                        four                         four + sov pick

NET gain:

nothing               zero picks, 1 levels      zero picks, 2 levels       zero picks, 3 levels      1 pick, 5 levels     2 picks, 6 levels

TL;DR Experience boosting picks might gain you a level ( or more) eventually, but unless you have seriously focused on them... that's about it.

Edit: My apologies for the formatting. This medium doesn't allow use of excel inserts or even the use of the tab key, but hopefully you can follow it.

All of those bonuses from Trainer, General, etc. DO stack, Carn112004, and with proper stacking can result in incredible (and abusable) bonuses. This is a good point. Should they stack with duplicates of themselves is another discussion entirely, in my opinion.

The 85% bonus xp (option 4) requires Potential 1 + Potential 2 + Potential 3 + Knowledge. So at a cost of 4 early picks, you will eventually gain 5 picks and 5 levels, for a net gain of 1 pick and 5 levels.

I'm not saying extra levels aren't beneficial, I'm just saying that Potential 1 is essentially a waste by itself as designed. No gain in useful level up picks, and you gain 1 extra level... 20 levels later. Not a win for me.

I would also agree that once you hit the +100% (and above) bonus xp marker the extra levels come fast enough to eventually overcome the power forfeited by picking them early. However, that requires a fierce dedication to them for the first 5 levels to obtain the full benefit.

In my personal mod I have been playing around with the idea of having increased bonus xp from these level up picks. Even with such changes, only sovereigns who focus on these traits in the first 10 levels gain any significant benefit. Thus the discussion about whether we (as players) feel these abilities are good picks currently. Of course, when army wide bonuses don't stack with duplicates of themselves on other units in the same army, it's much more feasible to make personal bonuses higher because of the more limited abuse potential. So maybe the discussions do relate to each other more directly.

Just for clarity... This post isn't a complaint about the vanilla game. It's just meant to facilitate a discussion.

If that discussion eventually improves the game, by eliminating duplicate army bonus trait stacking for example, then all the better.

I'm quite happy I posted it, since OliverFA_306 and Ulysses_31 provided me with the data I needed to take an accurate look at the impact of various levels of bonus xp gain.

to gain +10 spell resist individually requires 1 pick and +5 accuracy for army is 1 pick for defender, so +5 spell resist  and +5 accuracy individually would be equivalent to 1 pick. Of course, if one doesnt need accuracy and/or spell resist this is not worth it, but some builds need accuracy and spell resist, so for them the positive effect is there. Its no problem if some strats profit more from XP boost than other strats, thats with most picks the case.

If you want to use Paragon, you want those experience traits going. You can get up to 3 levels for one Paragon with all traits/bonuses picked.

But depends on your strat I guess. Wraith Sovereigns are bad for Paragoning  

Ok I did some math for you...

If deltaXP = 1.4 * lvl² + 8 * lvl, then it follows that the sum from lvl=1 to x of deltaXP(lvl) is:

XP = 0,4*x^3/3+8,4*x^2/2+(0,4/6+4)*x

So when does an XP bonus outweights the lost level ?

The easiest way to find out is to plot these equations.

Resuts: the best case for breakeven are (the best case is taking the bonus at next leveling, otherwise breakeven increases):

potential 1: 15% -> 15 levels

potential 2: 20% -> 10 levels

potential 3: 25% -> 8 levels

So OK, they are not completely worthless is you play at lower levels and get the chance to take them early, but on higher levels your heroes need to work not play

Perhaps they should change Potential from a percentage to growth, to just giving you a level.  Now you have a choice as to when you want to take it..early to reach a level to use an item faster, or later to maximize your level.