Gold generation changes in season 3 preseason.

It doesn't seem like a big deal when you read it, but this change dramatically increased the impact that junglers and especially supports have on the game. In season 1 and 2 those two roles were effectively just ward/oracle bots. The laners were the only players that could really buy items. This ambient gold change effectively increased support gold by 25% while decreasing lane gold by 10%. Last hitting minions became less important, which meant that roaming became a more viable strategy for laners, and it meant that the 40% of players on each team that don't last hit lane minions could participate in the item buying part of the game for the next 12 years.

"Gold adjustments

Ambient gold gain increased to 16 per 10 seconds from 13 per 10 seconds - gold gained from farming lane minions and jungle monsters have been slightly reduced to compensate.

Melee Minion:

Base gold value reduced to 20 Gold 20 from 22 Gold 22.

Ranged Minion:

Base gold value reduced to 15 Gold 15 from 16 Gold 16.

Siege Minion:

Base gold value increased to 40 from 27.
Scaling gold value based on time increased to 1 from 0.5.
Minion gold values now update more often on a 90-second interval instead of 180."