This guide is meant to provide a brief and basic guide on rune choosing, item pathing, and tips for specific champions. Not all champs will be included here as there are some I have no idea how to use.

-This guide is still in construction.-

I have been playing since late season 2, although only sparingly from S2 to S6 with occasional breaks (largest was more than half a year in S4). From preseason S7 I started to play better and more. In Summoner's Rift I main both botlane roles.

As of now(late 2018), I have 2100+ ARAM games with a winrate of 51.5%-52% (sometimes go out of the range but generally sticks to it).
I have 1100+ normal games with the same winrate range as ARAM.
I may have 500-1000 ranked games so far, never took the time to count.
Last but not least I have 500+ bot games (I have no idea how I lost some, though).

From whatismymmr.com, I currently stand at 1735(top 27%), but I have bounced around from around 1650(top 27%) up to 1950(top11%). This is not a high mmr, but I believe I'm credible enough to give at least some basic advice for someone who wants to get out of really low ARAM mmr games or tryhard.

The General section for items and runes are really general, follow it when you have no idea what to do and have no time. For that section I've split all champions into several broad groups, namely ADC, Mage, Tank, and AD (or bruiser). I know this is not an accurate portrayal, but I want to keep it brief unless I get to specific champions.

Also, as this is my first attempt in setting up a guide, and the notes in the spell/item/rune section has no formatting, I'll keep this guide text-only until I finish it and have time to look up the use of BBCode.

Almost all champions benefit from flash. That is, unless you choose to go ghost and snowball on, say, Hecarim, so I'll assume you take flash in a slot.

Heal is great in this map due to the inability to back. Similar to Summoner's Rift, champs take Heal for healing and a short burst of speed to improve positioning. Great choice for ADC and Mages.

Clarity is excellent for early game mana issues. However, it starts to become useless around after the 10-15 minute mark. Nonetheless, it is a really viable pick for those who have lots of poke. More early poke will likely give you an early advantage, which you could use to win. Definitely take on most Mages and certain ADCs.

Mark, or snowball, is really nice for those who need to go in. Anybody can use it, but usually it's the tanks or bruisers who take it. Long range champs might want to restrain from taking this for better positioning. A nice trick with this is you can possibly use it to escape if you snowball a minion far away from the enemy.

Barrier is nice for shielding damage, and works better than heal when because it has a slightly larger number and isn't affected by healing reduction. Downside to it is that it's temporary. I personally don't like people taking it because it's a selfish version of heal, but it's a good spell overall.

Ignite is also a really great dueling spell. Take it when you don't want to snowball in but still want more offense.

Exhaust is nice, but usually not chosen because there's always a spell better than it. In SR, usually supports take clarity, but in ARAM, I'd recommend supports to take clarity instead. If you're certain you won't run into mana problems, then definitely take exhaust.

Ghost is nice on champs who benefit greatly with increased mobility. Great for skirmishes or skirting the fight but in most cases there is another spell better than Ghost.

Cleanse is powerful, but you risk not using it ever in the game. If the enemy doesn't have any hard cc, it's easy to forget you have Cleanse, and that's a waste of a summoner spell. It's a gamble. Not recommended, but possibly comes with a high reward.

In the following sections, I will give a brief overview of what to note and what to build on that type of champion. If you have no idea what to build on an enchanter support, follow the mage item build, etc. Specific itemization will be included for certain champions in their sections.
Builds are really similar to Summoner Rift games.

Important:

Build executioner's calling early if there are more than one healers on the team. It halves self healing and ally healing goes from half to quarter healing. This is the cheapest source of grevious wounds.

Lifesteal is really important on this map as there is no backing. If you feel like there is too much poke, build lifesteal ASAP.

At full build, you may sell your boots and/or Stormrazor for more sustained damage output or survivability.

Generally, start with a BF Sword if you plan on going Stormrazor first, or Vampiric Scepter with a dagger if you build Blade of the Ruined King first.

For Zeal items, it might be worth building both Statikk Shiv and Rapid Firecannon on any ADCs just for the pushing power and burst.

Choose a lifesteal item acoording to the enemy team comp. Botrk for tanky matchups, BT for lots of poke or Mercurial Scimitar for the QSS.

Frozen Mallet and Maw of Malmortious are great choices as defensive items. Usually, build Frozen Mallet against AD heavy teams, or an armor item of you're comfortable with the reduced damage, and get a Maw of Malmortious against AP teams.

Example build:
Berserker's Greaves, Stormrazor, Statikk Shiv, Rapid Firecannon, Infinity Edge, Blade of the Ruined King

Important:

Always prevent yourself from running into mana issues early on by building Lost Chapter of Tear of the Goddess. Early poke means an early advantage, which is important to winning the game.

Against all-squishy teams, Sorcerer's shoes with Morellonomicon negates 33 Magic resist. That is all, if not most, of the MR they have if they didn't build it. Having a Void Staff on top of that likely puts them in negative MR.

Go for Luden's Echo if you can poke. If don't have reliable poke, try Hextech GLP-800. The slow is really good at setting up yourself and your teammates. Only go for Archangel's if you really need the mana or need the shield desperately.

You may build both Luden's and Archangel's staff, but It will set you back in buying other items. Not recommended but a possible build path.

Generally, start Lost Chapter for most mages for the mana regen and AP. Rush the finished item from Lost Chapter unless you're going for Archangel's staff. In that case, it might be better to upgrade when you have at least 400-500 stacks on Tear of the Goddess.

There are much more defensive options for mages than ADCs. Go Banshee's Veil or Abyssal Mask(not that recommended) for Magic Resist, or Zhonya's Hourglass for armor. Liandry's Torment and Morellonomicon are great health options.

Example build 1(more damage):
Sorcerer's Shoes, Luden's Echo, Rabadon's deathcap, Morellonomicon, Void Staff, Zhonya's Hourglass

Example build 2:
Sorcerer's Shoes,Hextech GLP-800, Rod of Ages, Morellonomicon, Liandry's Torment, Zhonya's Hourglass

Important:

Generally,

Example Build 1(against AD):

Example Build 2(against AP):