Balance/Stats

Attack:
Statistics for 3D6:
Source: Source with more details
In a nutshell for these rules (I NEED TO DOUBLE CHECK THESE)

- If defense points = 12  then the chance of hitting (=13 or above) is 25% (one in four)
- If defense points = 11, then the chance of hitting (= 12 or above) is 37.5% (about one in three)
- If defense points = 10, then the chance of hitting (=11 or above) is 50% (one in two)

- If defense points = 9, then the chance of hitting (= 10 or above) is 62.5% (about two in three)
- If defense points = 8  then the chance of hitting (=9 or above) is 75% (three in four)

Damage:
Very easy -
Hit points (average) per successful attack roll (above) = 0.5*number of damage rolls
So "Hippo" with 2 damage rolls = average of 1 HP per successful attack roll
So "Dino"  with 3 damage rolls = average of 1.5 HP per successful attack roll

Damage per round:
= Number of attacks*Attack probability * Damage probability

For an opponent with defense 10:
So "Hippo" with 3 attack and 2 damage rolls = (3*0.5*1.0) = 1.5 damage per round
So "Dino" with 2 attack and 3 damage rolls = (2*0.5*1.5) = 1.5 damage per round

For an attacker with defense 8:
So "Hippo" with 3 attack and 2 damage rolls = (3*0.75*1.0) = 2.25 damage per round
So "Dino" with 2 attack and 3 damage rolls = (2*0.75*1.5) = 2.25 damage per round