Hero Level

Heroes gain levels while you play games with them. The amount of XP gained is equal to amount of gained in the game, plus 50% if you have alternate outfit bought for the hero. You can also gain XP if you select an already max upgraded card from the pack (as listed here). Each level gained rewards a 250 bonus, and certain levels will unlock/upgrade that Hero's card: The card is unlocked at level 4, upgraded at level 8, and max upgraded at level 28. Please note that while getting hero level 8 (and thus 2nd level hero card) can be done in a single day with some effort, getting hero level 28 is a tedious and time consuming task, possibly requiring weeks or even months of playing, due to the way XP required for level is set.

XP required to level up from level $n$ is equal to 1.2 * XP required for level $n-1$, which makes it growing exponentially quite fast. The exact formula is:

$XP_n = round(1.2^{n-1} * 300)$

The actual values used in-game are presented below for your convenience, up to level 30. The levels that you unlock/upgrade hero card are bolded (4, 8, 28). Note that the total amount of experience required for level 28 is about twice the total amount required for level 24, i.e. it takes about the same amount of play time to level from 24 to 28 as to level from 1 to 24.

Hero Level	Total XP	XP to level up
1	0	300
2	300	360
3	660	432
4	1092	518
5	1610	622
6	2232	746
7	2978	896
8	3874	1075
9	4949	1290
10	6239	1548
11	7787	1858
12	9645	2229
13	11874	2675
14	14549	3210
15	17759	3852
16	21611	4622
17	26233	5547
18	31780	6656
19	38436	7987
20	46423	9584
21	56007	11501
22	67508	13802
23	81310	16562
24	97872	19874
25	117746	23849
26	141595	28619
27	170214	34343
28	204557	41211
29	245768	49453
30	295221	59344
31	354565	71213