This racial bonus improves the Planet quality of your planets. * Green Thumb (+10%) cost: 3 points * Magical (+20%) cost: 8 points It gives more green tiles on planets. However the bonus is always rounded down, limiting its effectiveness somewhat. Slightly more useful in DL where a planet gets TWO new terraforming tiles if it is class 15+, and 3 if it is class 25+. That effect is not present in DA or TA.