The dice aren't loaded, you're just seeing a binomial distribution[1][2] :)

[1] http://en.wikipedia.org/wiki/Binomial_distribution [2] http://hyperphysics.phy-astr.gsu.edu/hbase/math/dice.html#c2

There's actually 2 dices, so there are quite a few more ways to get a 7 than to get a 2

7 = 1+6, 2+5, 3+4, 4+3, 5+2, 6+1

2 = 1+1, 1+1

Or, the difference between 1d12 and 2d6 (roll of one 12 sided die, vs summing the roll of two six sided dice).