Malphite, at least in lower ranks, is extremely easy to play, and difficult to fight against after level 6. Point-and-click slows, good damage, great teamfight. AP Malphite takes advantage of these strengths to play a pseudo-assassin, with terrifying burst power, in exchange for losing his sustained fighting power.

He can also fill a support role, slowing down champs for his ADC/jungler to chase and disabling ADC champs with E. At 6, he becomes a great engage support, and can easily end teamfights before they can actually begin. That being said, you are essentially a worse Maokai in this role, so keep that in mind. You work far better with APCs compared to ADCs.

Note that this guide is still a work-in-progress, and will get more matchups as time passes, especially for support matchups.

Pros > Safe blind pick > Easy to use > Great teamfight initiation > Simple laning phase > Can flex into being a tank > Insane damage potential

Cons > Stubby range outside of ult > Does poorly into AP comps > Ult is fast, but not undodgeable > Immobile on his own > Vulnerable outside of ult > Falls off if severely behind

Until your first back, you might have a rough time. Malphite is incredibly mana-hungry, and mid/bot lane has a lot of poke. Your worst matchups are gonna be mobile burst champs ( Zed, Ahri) in midlane and all-in supports ( Leona, Taric). In these cases, play it safe and work for your level 6. In midlane, you can take Doran's Shield if you expect to be poked out a lot more than normal.

Seismic Shard should be saved to poke out your laner when Comet/Manaflow (if you took it) are up, since you need to make the most of the big mana cost. Ground Slam is used for wave clear as well as abusing any potential AD champs in lane.

In both lanes, you're esentially playing footsies with your enemy laner. You can be agressive with your Q, but keep tabs on where the enemy jungler is. In a poke lane, dodging poke is imperative because your Q has deceptive range, but usually is shorter than most spells.

In support, your E can really hurt AA-dependent ADCs, but they can still run you down if you don't play it smart. Work alongside your laner and focus down on one target. It worth picking up defensive boots or Seeker's Armguard if you want to protect your laner a little more by soaking damage.

Everyone loves Malphite's ult, it's a defining part of his kit. However, if you're serious about playing him AP, you need to learn to use his Q smart. It's decent damage and an equally-decent slow, but it's also your only safe ranged option. It might be tempting to chuck rocks at your laner, but you'll lose everything in lane for it. Prioritize making the most of it by using it only when runes like Scorch+Arcane Comet are up. In riskier matchups like Azir, the Move Speed + Slow is the difference between winning trades and losing lane. If trades altogether are too risky, it might be your only chance of securing CS safely. Think ahead before using your Q...at least until your first back.

If you played safe or even got a kill/assist early, your first back is going to feel great. This is especially so if you picked up a Lost Chapter, with Malignance as your first priority to ult your laner/other lanes more frequently. Now you can play more agressively, spam Q's and punish your laner. If you poke your laner with some Q's, you can potentially solo-kill them with Unstoppable Force. Alternatively, look to roam and and support your lanes/jungler.

If you're behind in lane and can't risk an all-in anymore, work on roaming and affecting the rest of the map. Your ult can flip a fight easily, and even the mere visual threat of a 6+ Malphite can affect your enemies. I recommend taking Lucidity boots early for the cheaper cost and more frequent Q's in this case, as the priority is now supporting others instead of outright killing people.

You have one goal: diving squishies. If you got the lead early, you can effectively snowball to the point of one-shotting anyone that isn't a tank or bruiser, and you can still solo kill most of them if you aren't behind. Bear in mind, while this build hurts, it can fall off if the chunkier enemies reach full build, allowing them to itemize better against you.

Sometimes, even if you have a great lane, your team may not. Even when stacking full AP, its hard to fight things like a fed AD toplaner/bruiser jungler. I've had multiple games where pivoting to building armor after Malignance did a lot for me, so it's worth keeping this in mind. Sometimes its worth giving up the comedic one-shot power in exchange for dragging your team to victory. This also becomes an issue with botlane if an AD botlane got ahead, so stacking armor and working with the team gives a lot of value.