Also how do you get 6d6+15? I only see 4d6+12.
A lance is a normally a two-handed weapon that deals 1d8 damage for a medium character, but it has the following special rules:
Lance: A lance deals double damage when used from the back of a charging mount. It has reach, so you can strike opponents 10 feet away with it, but you cant use it against an adjacent foe. While mounted, you can wield a lance with one hand.
Because a medium character can wield a medium lance one-handed while mounted, they can also wield a large lance two-handed while mounted for a piddly -2 to attack rolls for using an Inappropriately Sized Weapon. I'm willing to do that because going medium to large on a lance makes it go from 1d8 to 2d6 as the base damage, as per
Table: Tiny and Large Weapon DamageThen we bring in the following feat:
SPIRITED CHARGE [GENERAL]
Prerequisites: Ride 1 rank, Mounted Combat, Ride-By Attack.
Benefit: When mounted and using the charge action, you deal double damage with a melee weapon (or triple damage with a lance).
Which brings us up to 3d6 weapon damage. The +15 is due to the fact that two-handed weapons get 1.5 times Str mod added to damage instead of just adding Str mod.
In my case, that's 3*1.5=4.5, rounded up to 5 and multiplied by 3 for 15. If I spent the points for 18 strength, I'd do 4*1.5=6 and then 6*3=18 damage, but the extra 3 damage isn't worth the huge point-buy cost of going from 16 to 18 strength.
E: The allowance for 1 flaw COMPLETELY changes my character build. Now I'm making a Human SORCERER who focuses in Donkey Mounted Combat using Spirited Charge using an Inappropriately Sized Lance.