Since Fizz can move through units, find opportunities in lane to walk through minions and apply your Seastone Trident ability - the damage will rapidly add up as the opponent's Health drops.
Fizz's ultimate ability, Chum the Waters, can be aimed at an enemy or towards the area where you think they'll be going. Even if the lure doesn't connect, the threat of an impending shark can often force opponents to waste time moving around the danger zone, or split up a tightly grouped enemy team.
Although primarily an AP scaling champion, Fizz's spells rely heavily on his auto attacks and the on-hit effects they apply. For this reason, he has high synergy with Sheen items as well as Hextech Revolver, and an early combo of the two can often catch opponents off-guard, as a single use of Urchin Strikewill proc both item effects at once.
Fizz has kill pressure as early as level 2 and 3. If you can get your first level before your opponent, an aggressive engagement can often force an early flash.
Playful/Tricksteris a strong ability, but don't let it trick you into thinking you're invincible. At early levels it costs a large chunk of mana and you'll likely only be able to use it once or twice in lane before having to refill, and the cooldown is quite punishing. Try to be conservative about using it early on.
Fizz can use Urchin Strike on enemy minions in order to get closer to opponents or further away from them. This can be used to evade skillshots and escape from ganks without putting the more valuable Playful/Tricksteron cooldown, or to extend your effective range in ways your opponent may not anticipate.
A full combo from Fizz is extremily powerful once he has some items, but trying to take a laning opponent from 0 to 100 in one engagement can often put you at risk, especially in situations where you can't manage to engage with Chum the Waters. In many cases, choosing to whittle down an opponent through smaller trades beforehand is a much safer option.
Playing Against Fizz
Playful/Trickster may be a very annoying ability, but the moment it goes on cooldown, Fizz's defensive and offensive options are limited. If he uses it to engage, he'll need to auto attack, then wait 2 seconds for his mark to primebefore attempting to execute his opponent, during which time he's entirely vulnerable to crowd control and retaliation. If he uses Urchin Strike to engage, he'll need to walk into range first, often telegraphing his intentions. During Urchin Strike's dash, Fizz is vulnerable to all attacks, and so after engaging this way he'll often opt to use Playful/Trickster right away in order to avoid taking too much damage and secure his kill. In either case, understanding what options Fizz has available to him after applying Seastone Trident's passive bleed and recognising how and when to punish him will make fighting against him much easier.
Fizz is best in extended skirmishes - don't chase Fizz if you can help it!
As an Assassin, Fizz needs to kill his target or disengage safely, as his ability to deal damage drops off heavily when his spells are on cooldown. Buying mixed defensive/offensive magic resist items such as Hexdrinker or Banshee's Veil can let you survive his burst and trade back while he's vulnerable.
Keep your eye on Fizz's CSing in the early game. If he misses out on resetting Seastone Trident's active, the ability will go on full cooldown. Consider trading with him when this happens, as he won't be able to cash in on a good amount of his potential damage without it.
As an AP melee attacker who typically doesn't rely on attackspeed, Fizz often lacks the ability to pressure towers. Having no self-sustain, he also often ends his winning trades and skirmishes on low health, without the ability to safely push up and take full advantage of his victory. For this reason, many Fizz players choose to try and roam and get kills if they force their opponent out of lane. Punish him by pressuring his tower and warn your teammates if he leaves.
Even fish know there's safety in numbers. Fizz may be good at bursting down a solitary target, but because his assassination and escape patterns rely so heavily on a single move, he's often ill-suited to diving into a co-ordinated back line on his own. Stick with your teammates and try to bait out his only escape, then focus him down.
If Fizz lands his ultimate, Chum the Waters, he'll often try to approach at a rate that will allow him to safely Urchin Strike in right as his target is knocked up, proccing Seastone Tridentand allowing him to conserve Playful/Trickster for escaping while avoiding retaliation from his opponent. During this time, try to force him to use Playful/Trickster to secure his kill by throwing out a damaging spell or crowd control as he moves into range. You might not survive, but you'll make it much easier for your nearby teammates to avenge your death and snare some juicy shutdown gold.
At level 6, Fizz can guarantee a kill on a squishy with Ignite, Chum the Waters, and an entire spell rotation, in some cases even when you are a little behind.
At about 400 AP, Fizz has the potential to one-shot squishies without using Chum the Waters, or R > Q > W followed by E to escape.
With the new updates on fizz's abilities,forget about maxing e.Max w first and use it to farm every minion.Safe and drains very little mana if you execute the minions with your w,which is very easy to do,especially with a sheen and couple of dorans.Also don't forget that w resets your autos.Wave in as many auto's as possible.
At level 3,use q to the enemy mid laner,auto and than e.After you come down from your e,your w should be ready to use for its 3x dmg.So after you come down from e,auto than activate w for the auto reset.At this point most enemy laners should be at a quarter hp,so if you have ignite use it and keep auto than finish with your q.With sheen and 2 dorans fizz dominates anyone in trades in terms of damage.
At level 6,try to pull the giant fish ultimate,as it isn't as hard as it seems.The hitbox is very large.Than follow with q e and finish with your w for the 3x damage.The ult is also perfect for roaming,especially ganking top.
Thunderlords is very easy to proc, if you want burst.Other keystones that are worth mentioning are Stormraider's Surge and Deathfire Touch.The former makes you very slippery and it is easy to proc with fizz's w, especially with a sheen, and makes trading in lane very safe against skill shot reliant opponents or melee.The latter gives more damage than Thunderlords in extended trades.Fizz q and w active are both single target and work very well with Deathfire Touch.Q alone will have a 80% ap ratio instead of 55% if you only hit it.
Cooldown reduction is very important on Fizz as he relies a lot on his cooldowns to do damage and escape. Nashor's Tooth or Morellonomicon as a first item is highly recommended.
With the new Hextech Protobelt-01, Fizz can take advantage of every stat it gives.Mobility, cooldown, health, burst and damage.Can be used to close the gap for a Q or escape.
In lane, before level 6, Fizz can be harassed by most mid laners, if he doesn't have enough mana for an e.He can be killed right away if you have a level advantage or a few kills on him.He is most vulnerable right after he uses e(either to farm or avoid damage).
Fizz's q can miss.Blinks like flash or even dashes can avoid fizz's q, which can be a lot of damage with a lich bane passive.
Fizz's kit is very flexible and a good fizz player doesn't have much counters mid lane.Fizz can change his skill order or even buy certain items to get an advantage mid.Maxing w over e is a good tactic to ensure fizz doesn't push too much and can farm easily under tower if needed.
Rush negatron cloak, double doran's, boots and pots.If fizz plays aggressive trade back after he wastes his abilities,stay inside your minion wave when he uses e on you to make him push the lane.Don't push against fizz,one well placed ult and he kills you.Zonya is also recommended,but it takes a while to build it,negatron into main first item is recommended.Ask for junglers help when he pushes and engage when his e is on cooldown.
Fizz is slippery, but squishy.In teamfights if you manage to cc him he will die fast.He relies on his skills and cooldowns to avoid damage.He can't tank damage well.Zonya is a great tool agains fizz inteamfights.
A couple ranked games with Fizz will teach you his pros and cons, so when you will meet him later as an opponent you will know what to do.
Always ward the your lane after he hits 6 and be very wary of his ult, it can set up a nasty gank for his jungler.Flash his ult if necessary,don't get caught by it.
Don't let Fizz trick you.Never follow fizz in the jungle unless you are certain he can't kill you.Never follow fizz when he leaves mid to roam top or bot.He can just hide in a bush and ult and kill you.SS when he leaves lane and push your lane or go roam to the opposite lane.