On difficulties lower than Hard you can mess around and play a lot more sub-optimally than this. YMMV, and consider lowering the difficulty or playing non-Hardcore (HC, i.e. permadeath) if you get frustrated and don't want to spend time and effort researching and learning the game mechanics.

Depending on your accumulated gear, skill, and time, there are many different ways to play the Alchemist class. For example, a pet/minion-heavy approach will generally be easier and safer. This is not that guide, as I prefer a shooty ranged mage style.

Winning the game: The person who wins playing games like this is the person that has the most fun doing it, given the time, skills/experience, and effort at their disposal. If you just want to see all of the game's story and locations, just play on Easy mode and blow through it. HHC is for the highly skilled or those inclined to go slow and methodically. Completionists, have at it.

Each time you level up you will have 5 points to distribute.

Generally: 2 MAG, 3 DEF.

Specifically: You will find yourself with gear in your Shared Stash that has STR requirements. You can either put points into the relevant skills or toss a few into STR as necessary to use really good gear at lower levels than you otherwise would. It's generally worth it if you have a really good weapon available, but only as needed. You will also get +STR on items when you enchant them, and can put gems into sockets as needed.

WARNING: You may find yourself with very unstable gear/stat requirements, to the point where just hitting 'W' to switch weapons leads to unequipping gear and being unable to put it back on until you get your stats up. Yep, it's an old game and there's weird stuff sometimes.

LEVELING STRATEGY:
If all you do is the main quest line, prepare for a very hard time. Bosses don't respawn so can't be farmed. But the monster levels of the main dungeon quest areas stay the same. If you do the side-portal-quests, then you will have a comparatively more difficult time there, but an easier time in the main quest dungeons. However, the side-portal-quests, given by Hatch in town, will always scale to have monsters one level below the player character. This means that they will become very dangerous after about level 10 or so - do as many as you can early on, then decide if you want to mess with them or not. It's just an achievement and some pretty crap quest rewards, unless you mod that part.

The only way I've found to make money and leveling easier is to buy maps from the map vendor that are titled as below your current level. This will ensure that the map portal will lead to an area with monsters of a lower level than you, enabling you to gear up, make money and earn 'fame', while practicing your skills for the main events.

For a mostly untwinked character:

LEVELS:

• 2-4: 1 pt in Magic Weapons Expertise (MWE), 1 pt in Nether Imp (unless you don't want to respec later on, as that skill's usefulness is later dependent on heavy investment elsewhere), 1 pt in Armour Expertise when you have a piece of gear that needs it. Rest of points in MWE unless you can shoot Ember Bolt (EB) more than 12 times with one full mana pool. So take your total mana pool, divide by your current EB points cost, if the answer is 12 or more, put a point in EB. Ember Shock is useless outside of very specific builds unless you have specific mods/skills/gear to support it.
  
• WEAPONS CHOICE:
  Wand + Shield is safe(r), and helps with popping off TNT Barrels. Dual Wielding wands is faster early, though offensive skills become so powerful in late game that you will rarely use your wands for shooting unless specifically gearing/investing skill points for it. Staves are usually higher DPS but when out of mana (OOM) you are poop out of luck and have to run away or hit someone over the head, which is risky business in hardcore. If you do decide to forgo using a Shield,
  YOU HAVE BEEN WARNED. YOU'RE GONNA DIE.
  Always check the merchant for a new wand every time you're in town, and have some money saved for when it does appear. Also check the fish monger if using the Merchants mod, for the Trufflesnout fish.
  
• 5-9: 1 pt in Ember Shield, 1 pt in Pet Mastery for your pet and any Skeletons/Zombies/Nether Imps you may have out. Putting a Skeleton or Zombie spell on your pet is an easy way to make sure you have some distraction for enemies. Rest of points in Critical Strikes unless you can shoot EB more than 12 times with one mana pool. Ice Shock/Thorned Minions appear not worth the points unless using specific gear/mods. Look for the Heal All spell early on for your pet, which will give semi-random healing (usually when going into combat or when not needed).
  
• 10-14: Respec (see Respec potion mod) the point in Nether Imp to 1 pt in Alchemical Golem unless you have enough Skeletons/Zombies running around, drop all points in EB for Ember Lightning, up to the point where you can shoot Ember Lightning about 10-12 times on one mana pool. 1 pt each in Adventurer and Offensive Spell Mastery. The latter becomes useful when you realize how overpowered the Elemental Overload + Ember Lightning/Ember Lance combo is, esp. for named champion monsters which otherwise can become dangerous and difficult. If you prefer Ember Bolt to Ember Lightning, keep in mind that Ember Lightning shoots around corners and through walls/floors more easily, is not blocked by terrain, more fire-and-forget, has some target-seeking behaviour, but does not (do as much?) Knockback. Infuse is not worth the points as offensive skills outstrip weapons damage later.
  ALTERNATE: Once you've died a few times and know what you're doing and how you have to save up gear to outfit your next victim as you learn the game and how to survive while continuously dying, you can plan ahead and not put any points into EB.
  
• 15-19: 1 pt in Ember Lance with Elemental Overload active is pure magic for killing named Champion monsters that are Found & Fixed in position by your pet and/or summons. Then switch back to Ember Lightning for general mobbing. 2 pts in Terror can be very useful, though running away usually works as well. Rest in Ember Lightning and Critical Strike. Frailty is too short-range to be useful, and using weapons for general shooting dps will make the game artificially harder.
  
• 20-24: 1 pt in Pyre to test it out, then Respec out of it and consider respeccing out of MWE if you no longer use wands for shooting dps, which will cost you 15 000 g. 1 pt in Ember Phase. Rest in Ember Lightning until your mana pool goes empty too fast, then Critical Strike, then Block & Parry if using a Shield, then Adventurer/Advanced Spellcasting/Barter. By this point you will have realized that a large amount of the game revolves around managing money, as buying gear in town and enchanting it in town or going on already cleared dungeon enchanting runs takes time/money. Adventurer allows you to downrank potions, and allows you to increase player character (PC) power relative to the set monster levels in the story dungeons, and the floating (PC level -1) monster levels in the optional Hatch quest dungeons and the optional Map dungeons given as quest rewards and sold in town.
  
• 25+: 2 or 10 pts in Beam Golem, 1-10 pts in Ember Strike (easy to target monsters that can't hit you), 1 pt to test out Ember Sentry (then pay 15 000 g to Respec...), 0-10 pts in Treasure Hunter if your damage and mana recovery skills are maxed.
  
• NOTE: Before starting a new area, go through all your gear and spells to identify areas in dire need of upgrade, and consider doing a Hatch quest or a Map dungeon (bought from vendor or given as a quest reward) to make some cash to buy gear. All your gear should continually be either very good, or at least have level requirements somewhat close to your current level.

• Elemental Overload - incredibly useful with Ember Lance for taking down named Champion monsters. I recommend placing this on hotkey 3 and keeping a finger on that key as you run around in dangerous-level monster areas. You can also rebind hotkeys with mods.
  
• Elemental Protection - run away instead of taking the time to cast this, unless using mods to extend buff times. CORRECTION: Use it for when you know you're going into something bad, which is really mid-to-late game.
  
• Dervish - VERY useful for shooting wands/ranged weapons as dps, or in combination with your main attack skill. Combine with EO for maximum burst. Add some +% Faster Cast/Attack speed for machine gun wanding.
  
• Web - very good immobilizing spell, with the problem that taking the time to cast it takes away from actually using damaging spells. Try it out, then probably focus on killing faster and/or running away.
  
• Silence - not reliable enough to take the time with.
  
• Identify - useful if you don't have a mod to do it for you.
  
• Haste - useful for Enchanting Shrine runs, and not much else.
  
• Summon Zombies - useful on your pet as an auto-cast spell.
  
• Summon Skeleton - VERY useful on your pet.
  
• Summon Flaming Sword - useful if you don't like the aesthetics of summoning zombies/skeletons, but a very short duration makes it less useful. Looks cool.
  
• Summon Blood Skeleton - VERY useful
  
• Summon Skeleton Archers - situational only, or if you have better skills than I. Don't put it on your pet.

Due to the fact that money management is a huge part of the game, I recommend not updating your spell scrolls and your pet's spells more than every other spell level, so go from Elemental Overload II to IV instead of buying III. This presupposes the Merchants mod.

Rings and Necklaces should almost always go from what's equipped on your character to your pet when you replace yours. Focus on +Health/+Damage items usually found on Green Rings & Necklaces - or purely defensive stats, as your pet is useless when fleeing, and will be fleeing plenty if you don't constantly feed it health potions/healing.

The default auto-cast spell combo that is proven to work somewhat well is Heal All and Summon Skeleton. Keep in mind that your pet is most likely to use a spell as soon as it gets into combat, with no regards to line of sight or actual usefulness of said spell. Your pet will frequently be fleeing when it could just as easily simple heal itself, though the hidden spell cooldown does play into this.

ALWAYS. FEED. FISH. TO. YOUR. PET. Any fish, with the possible exception of the Spider transforming fish, immediately improve your pet's usefulness and fighting power. Use a mod if you, like I, don't like fishing. Keep Frenzy Fish and Prismatic Moray fish for specific difficult situations. As far as my Google skills can tell, they stack with each other and with the transforming fish.

There are many mods that change the appearance of your pet, to include turning your cat into a panther. Unfortunately many pet skin mods conflict with other mods and may not work.

• The Blacksmith in town is a very good source of gear. Which sucks if you prefer to run around killing monsters, but oh well, this is an old game and you can try to mod it if you care.
  
• Items with +Health are VERY USEFUL when playing VHHC, so think twice before replacing them, even with obviously powerful offensive stat items.
  
• As an Alchemist, +MAG stats is never wrong, but +STR is often useful to allow you to use gear. Keep in mind that if you're right on the edge of being able to equip something, using the Enchanter or a gem in a socket, or both, may be the ticket.
  
• VHHC Torchlight 1 is a game of staying alive and managing money. Mods, skills, and going slow can make this easier.
  
• Learn to stutter-step your attacking and mana/health-potion quaffing (remember Rogue on IBM PC?), and also learn how aggro works so you can reliably get your pet to run ahead of you.

• Vendor Enchanting in town - expensive but well worth it on VHHC. Once you have lots of money, look at each piece of your gear, identify weak spots, go check the vendors for replacements, and decide how much money you'd like to spend on enchanting. Keep in mind that you'd also probably like to purchase new spell levels for you and your pet, assuming you have the spell vendor Merchants Mod.
  
• Shrine Enchanting - cheap but time consuming, in that you have to keep a record or remember where the enchanters you meet in the dungeons are, then run back to them after they've respawned. Respawn usually happens once you've visited 5 other maps.
  
• The above behaviour can be exploited by using the town Dungeon Portal by going back to the map of the first boss fight, where there are four chests you can open without encountering any monsters. The average haul from cash and loot is about 600 g.
  

For further details, see http://gtm.you1.cn/sharedfiles/filedetails/?id=490358813

Mines
Set pet on Aggressive. Focus on learning the game mechanics, staying safe, and getting a decent weapon before you fight the first boss. Don't forget to buy some potions before the first boss or you will be doing a lot of running around. Check vendors for cheap Rings/Necklaces with +Damage for you and your pet. +HP/+Damage items are ideal.

Necropolis
Beware Spectres - they will teleport on top of you. Consider doing a Hatch quest (Hatch is an NPC in town) and/or a Map quest (available from vendors or as a quest reward) to make sure you over-level the monsters in the storyline dungeons. Yes, the varying monster levels can be confusing - they are set at a certain progression in the main dungeons, but start one less than your current level in the Hatch and Map dungeons. If monsters are the same or one level less than you, stop, take a look at your gear, identify specific items to improve, consider respeccing (costs 15 000 g, only available with an - officially approved - mod), slow down, or do a Hatch or Map dungeon. To improve the quest rewards, use a mod. Beware fast rushing Skeletons and teleporting Spectres. Watch the minimap for unexplained small breaks in the border of rooms - this may indicate a hidden treasure room.

PHASE PORTALS
By now you've encountered a Phase Beast. Always kill them, then make an educated decision on what to do next. Once you go in, you can't get out unless you get to the end. 95+% of Phase Portals will be easy at < level 20 or so, but if you go into one from a level that you're fairly stretched at already, prepare for a hell of a surprise. Dark Zealots, monsters you've not seen before, lots of clutter on the ground making it hard to see, and a boss you've never seen before - all moving way faster than anything you've seen so far. ...And that was the end of that run, now you're dead and rerolling another character. Beware of any environment terrain you've not encountered yet, and go VERY SLOW. Have minions out in front and consider shooting from off screen and resting for mana. DO NOT aggro anything you don't need to aggro. Consider always having one of each class at level 10 or at least past the first boss, that way you can always have a character that might use some equipment you find, and go 'mule' with them whenever your Shared Stash fills up. Unfortunately the Shared Stash is not moddable afaik.

Esteria
Beware small pygmies that get up close and are hard to see, even harder if you choose to play with item/gold drops always visible (click the looking glass icon on the bottom center left UI). Again, watch the minimap and general terrain features for sometimes cleverly hidden treasure rooms. Beware tricky terrain features like switchback stairs that play havoc with targeting, easily helped with Ember Lightning.

Primal Caverns
Beware charging Tu'tara monsters. Consider letting your pet go first on bridges, but to make that happen you first have to get in line of sight of a monster with your pet on Aggressive.

Lava-sunken Prison
Beware charging Goblinhounds and dynamite-shooting Goblin Archers. More LOS problems, solved with Ember Lightning. Final boss takes a while, but you'll figure it out if you're good enough to get here on HC mode. Or die and learn and come back with another character. You did plan out your next character, right? Plan for failure, expect a slog. It's really a roguelike game in that regard.

Dwarf Fortress
Respec for maximum Chain Lightning and some Meteor dropping. You may want to start keeping up Elemental Protection and watch out for the spooky ghost caster mobs. The ranged attacks will start to hurt. Also keep Terror handy for the swarms of Undead Dwarven Wights. I recommend a 3600 second Poison Elemental fish for your pet. And Summon Zombies. And go slow and methodically, for easy.

Black Palace
Better level up some first via the map vendor or have mad skills or lots of minions or go slow. Poison resistance is a definite consideration. Know what you're getting into when you turn a corner. Abuse LOS with Ember Lightning and Ember Strike + Elemental Overload. Ice Elemental 3600 pet highly recommended, as they stay away from mobs and need less healing/micromanagement. Also get a Healthy Pet mod.

Lair
TBD

After the End
TBD

Torchlight II
Go play it. Try some mods.

QUESTS
http://torchlight.wikia.com/wiki/Vasman for further information. Long story short:
The Gleaming Ember 1
Ember of Another Color 5
The Shimmering Deeps 12
Primal Caverns 18
The Savage Prison 23
The Strength of Ember 28
Deepest Ember 33

BREAKING NEWS: (No, really. I had no idea.) Turns out Chaos Gems bought in town (assuming this isn't a mod-only vendor, cba to check) are stupidly cheap. Hmmm, buy every time you're in town, almost. 200g/good gem is way too low to pass up.

• +Damage for your weapon, as mana/healing is easily gotten from potions, and elemental damage comes from various gear sources, but only +Damage helps with improving the damage of your main attack skills like Ember Lightning and Lance.
  
• +MAG for all other gear, unless you need specific Resistances. Resistances are not all that important in this game compared to Diablo II, but take a look at them once in a while and see if you can't at least have some in each category.
  
• +Armor/Defense is never wrong, if you have the gems available and don't really need them for something else, use them up as you'll get more soon enough as you level toward the end of the story, and can farm them up with a higher-level character.
  
• Chaos gems are rare, make sure to either keep the gear you use them in, in your Shared Stash, or destroy the item to recover the gem once you get better gear.
  
• Fished-up gems are even rarer, and may not drop with the IHateFishing mod.
  
• The Merchants mod allows you to buy gems (at a steep price), keep in mind if you all of a sudden need to meet a STR requirement or similar.
  
• Chaos gems cannot be upgraded by Duran the Transmuter. For further information see http://torchlight.wikia.com/wiki/Gems_(T1) and http://torchlight.wikia.com/wiki/Duran_the_Transmuter

Unfortunately transmuting isn't all that useful unless modded. See http://torchlight.wikia.com/wiki/Duran_the_Transmuter for recipes. The only one I've really found useful so far is 2 gems >>> 1 higher quality gem, as all other recipes negatively impact your cash flow, which is needed to buy new gear, enchants, or spells. It is possible to use the Transmuter to visit a special Horse Level at extremely high levels. Google for further information.

Modding this game is highly recommended, and mandatory if you want to respec your character with the - officially approved - Respec Mod. See http://www.runicgamesfansite.com/

I highly recommend the following mods:

• Torchlight Enhanced Textures (TET)
  
• IHateFishing
  
• Smarter Pets & Minions
  
• Merchant Pack
  
• Better Random Quest Rewards
  
• Healthy Pet Mod: Somewhat Healthy
  
• Items Always Identified
  
• Better Balanced Sale Prices
  
• Black Panther Mod
  
• Potions Stack Size
  
• Starch V2: Leviathan

I have yet to find a mod that increases the Shared Stash size. Installing mods is fairly straightforward, usually done by unzipping the mod to the C:\Users\YOURNAME\AppData\Roaming\runic games\torchlight\mods folder, or using the ModDrop client program (at your own risk).

• http://forums.runicgames.com/
  
• http://forums.runicgames.com/discussion/5630/vhhc-arcane-alchemist-ordrak-defeated
  
• https://www.gamefaqs.com/boards/960163-torchlight/52144759
  
• https://strategywiki.org/wiki/Torchlight/Alchemist
  
• http://gtm.you1.cn/sharedfiles/filedetails/?id=490358813
  
• http://www.runicgamesfansite.com/
  
• http://torchlight.wikia.com/wiki/Alchemist