How to actually counter Riven
- Pick

- Learn to freeze lane, Losing that 6 minions is better than losing your life, stay in experience range. If you successfully freeze the lane or lane gets pushed to your turret ask jungler to gank. Riven is mobile but she can be ganked as her abilities have medium cooldown early game.
- Don't dive Riven, EVER. Even if she has 1 HP do not dive her. I can't count how many times I have killed somebody (as riven) that dived me on low hp.
- Consider buying early armor against her, that 300 cloth armor might be difference between life and death for you.
- Don't trust my first advice if you don't know how to play those champions. Can't count how many times my mid lane Kayle has fed enemy zed because he saw that Kayle was Zed's #1 counter on lolcounter.com
- Consider switching lanes with ADC/Supp.
- Mute everybody.
And if enemy Riven is skilled then feel free to make Reddit and Boards post about Riven being op as fuck. Bonus points if you comment on Riven's wikia page.