How to Play Fizz in League of Legends

Leveling and Abilities

Use passive Fizz. Passive (Nimble Fighter) Fizz can move through units and receives less damage from basic attacks. Q (Urchin Strike) Fizz dashes toward an enemy unit dealing damage and applying on-hit effects. Fizz dashes a distance behind the enemy based on how close the enemy was to Fizz when the ability was cast. W (Seastone Trident) Fizz's basic attacks and Urchin strikes apply Grievous wounds dealing damage every second. E (Playful/Trickster) Fizz jumps toward mouse cursor being not targetable and lands back after a short duration dealing damage around him. Fizz can quickly reactivate again and he will jump toward the mouse cursor again dealing damage around him. R (Chum the Waters) Fizz unleashes a fish that hovers over terrain or latches onto an enemy champion. After channel, a shark will come up to eat the fish knocking back and dealing damage to enemies hit.

Take Urchin Strike at Level 2 and max it second.Take Seastone Trident at Level 1 but max it last.

Take Playful/Trickster at Level 3 but max it immediately. Take Chum the Waters at Level 6, 11 and 16.

Build Guide

Use Amplifying Tone or Crystalline Flask at the start. For mid game take Rabadon's Deathcap, Void Staff, Zhonya's Hourglass, Deathfire Grasp and Mejai's Soulstealer or Lich Bane depending on situation. You must build Zhonya's Hourglass and heavy AP.

Use mobility and ability power for masteries.

Focus on mobility, ability power and magic penetration for runes.

Use flash for summoner spells. You can take Ignite, Ghost or Cleanse too.

Laning

Harass opponents with a surprise Urchin Strike or Playful/Trickster. Note that you can cross a wall to Urchin Strike an enemy, but you can't dash through a wall after striking the enemy.

Use Playful/Trickster as a harassment move and a farming move.

Activate Seastone Trident before Urchin Strike if you can.

For team fights, try to open up with Chum the Waters.

Advanced Jukes and Combos

Run away with this combination: Use Playful/Trickster towards the enemy and don't reactivate. Wait for the enemy to get in range for it. If the enemy doesn't, reactivate. Then use Seastone Trident and then Urchin Strike through them. Tag the enemy with Chum the Waters and Playful/Trickster toward them.

If low on mana, for running away use Urchin Strike.

Use Playful/Trickster to hop over many walls. This includes the wall for Baron Nashor and the Dragon, the wall that covers the base and even over some walls like Anivia's Crystallize!

Use Playful/Trickster and then use Zhonya's Hourglass. It will deal damage around but Fizz will be still.