MosesPlays's Magma Orb Miner - 3.5 and on - ALL CONTENT- Low Budget - Videos Available

Level 88: https://tinyurl.com/yb8azdu7
Kill all bandits or help allira,if you need the extra resists(would make the build even cheaper)

6L: Magma orb - Remote mine - Minefield - Trap and mine damage - Concentrated effect and Greater multiple projectiles swaps to Slower Projectiles for single target.

Loreweave is the best option for the build with ample defenses and damage mods to compliment the build in ever way.
If you're just starting out the league and cannot afford it I could recommend you to go with shroud of the lightless,an extreamly underused body that fits so many builds. cheap,and easy to five link,I would drop conc effect and keep all the rest of the links.
Of course you can early on use a tabula and if it is really early in the league,this build would make a great starter,you could use just a 4 link setup or a 5Link on a rare chest with life resists. you could easily open up your atlas all the way to early red maps with just a 4-5 link because the shadow sabo class is such a strong starter.

A miner's helm has a high importance,because of the hybrid roll of shaper helms that gives level x remote mine \ PLACE AN ADDITIONAL MINE
this last part allows you to place another mine every time you place your mines.
This means that instead of placing only 3,you now place 4,which is a str8 up 33% more damage overall.
If this is a league start you might not get that mod right away,but once you do get it,the difference is noticeable right away.

For the helm enchant we go for +2 chain for magma orb,it synergizes well with our amulet.

After the 6L loreweave , this helm will be our most expensive gear slot,past that its peanuts,in terms of cost to be able to clear all content in the game.
But of course,like every build in POE,you farm with it,you get upgrades and it gets better and better the more currency you sink into it.

The enchant on a shaper's helm is what makes it a bit expensive,but you don't have to go for the enchant,you can go for a much cheaper increased magma orb damage by 40% shaper's helm if you are on a budget,but always remember that place an additional mine will always be better than getting a proper helm enchant,so you can farm your way up to it.

Early on in the league you are looking simply for a leather belt with life\resists.
Later on you can invest in something fancier like this belt here,a stygian vise fossil crafted(3sox res with scorched , pristine, prismatic) for life elemental damage and fire damage.. I was able to find this belt for only 2ex.. insta snagged it from POE.TRADE and went on to craft this jewel.

A hypnotic eye jewel,in this case I went for life flat cold to spells and increased crit if you haven't killed recently - the last mod inc damage if you've killed recently actually never applies.
Reason being: mines kill for us, so we never kill. this allows us to enjoy the crit if you haven't crit recently (again because we never crit but the mines do) but the drawback is that this specific abyssal jewel mod,does not apply to us ,again,because we never crit or kill anything ourselves.

It was important to me to get cold damage to spells,because we are a crit build,and since we crit all the time and magma orb is 100% fire,it was important to add flat cold to the build so that monsters freeze and shatter as we clear maps and delves and content,this is good defensively because well,we don't have to worry about post death monsters effect like spikes from porcupines for example.. and freezing and shattering makes the build feel really satisfying :)

A key item to the build is Gloomfang amulet.
A highly unused amulet and really cheap! this one you see right here cost me only 30c(!) it adds non chaos as extra chaos PER CHAIN and +1 to chains! which means with so many magma orb chains we are getting a huge chunk of chaos damage on top of all of our already absurd fire damage from the orbs themselves.I was able to get one with anger increased effect which of course gives us even more damage.

Ring 1 - Essence worm,
As with most Mind over Matter builds we want an aura,and since we cannot reserve mana at all to get the full defense effect out of our mana pool,we use this ring to get the buff as well as not reserving any mana,the drawback of course is the sacrifice of a ring slot,which could have been used for more damage life and resists,but it is totally worth it of course.

Ring 2 - Life Resists and stats.
If you need some strength or dexterity for your skill gems,here would be a good place to have it,as well,as much as you can have life and mana that you can stack on this ring. I went for the coral ring with some str and the resistances that I needed to cap at 80%.

No build related skill gems are currently socketed into my gloves.
Only some gems I level up for trading for chaos,because this build requires 3 buttons really.. well 4: placing mines,flame dash,phase run,and vaal RF for short but potent damage boost. that leaves a lot of room to level up some gems for extra cash.

-the gloves are just fingerless silk gloves with high life and resists,nothing fancy here.It just gives up to 16% increased spell damage implicit.

On the boots I placed a 4L: Cast when damage taken (level8) Enfeeble(level 5) Immortal call(level 1) and Detonate mines.

This 4L setup is a useful defensive mechanism that does 3 things when you take damage listed on level 8 CWDT: 1) curses enemies with enfeeble which gives them a 'weakness' debuff , 2) makes you immune to phys damage for a short period of time and 3) detonate all the mines you have placed already - This is used because sometimes we get stunned,and if that happens already placed mines will be detonated so the monsters that stunned you will die as you are being unable to perform any actions while stunned. - a real life saver.

Couple of words on the boots:
It is really important to me (and to you) to go for 30% movement speed.
Anything less will make the build feel slow,I would only settle for 25% MS on this slot if the stats were already amazing and the boots already had an enchant for the build,so I didn't have to run lab myself,but really try to go for 30%.Other than that,as much life and resists that you can afford.

BOOTS ENCHANT - Really important permanent boost to our character.
As explained before,as miners(and trappers also btw) we do not deal damage,we do not kill and we do not crit,not ever.(well,maybe with the exception of the rare flame dash crit).
This means we can enjoy permanent boosts to our miner(and trapper) such as(rated in order of strength for our)

1) damage penetrates 10% resists if you haven't killed recently
2) increased 120% critical strike chance if you haven't crit recently
3) adds 1-160 lightning damage if you haven't killed recently.

First one is the rarest of them all but still achievable if you spend the time doing uber lab,I would stop though,if I were to get any of the other two,because I just have no patience for lab.

Weapon links: phase run,vaal RF,and increased duration.

For the weapon,just pick ANY one hander that has spell damage critical strike chance for spells (80+) some FLAT COLD DAMAGE FOR SPELLS and some crit multipler.
If you can craft on your weapon the hybrid master craft: inc spell damage\non chaos as extra chaos damage - all the better! But don't stress yourselves out if you can't.

On the weapon as well,it was important for me to get high cold damage to spells in order to freeze and shatter all enemies.I also prioritized that in my abyssal jewel in the belt.

And finaly but IMPORTANT word on weapons for casters.. someone some time suggested daggers to be BIS for all and every crit spell casters.
This is nothing but BS I gotta tell you.. daggers are just as good as wands and as scepters.
Elemental damage for scepters spell damage for wands and global crit chance for daggers are all interchangable! what matters are the explicit rolls of your weapons.

Daggers are super expensive simply because they are popular and since they are more likely to roll attack mods rather than spell mods that makes them even more expensive because they are less likely to roll the mods that you want - spell daggers are rare and are NOT worth investing in.

Since flame dash was massively buffed,we don't use shield charge anymore,because well.. shield charge was nerfed and requires global attack speed to feel good now,and that makes wands and scepters a great and cheap and just as good and sometimes better than daggers.

I want you to take that lesson you now learned from me,and apply it on your future builds as well.

Shield 3link: Flame Dash + Faster Casting + Arcane surge.

YES! I do not dual wield... the build has plenty of damage and a good shield offers plenty of damage,as well as life and resists that makes it easier and cheaper to gear up your character!

Sidebar

Go for a shield similar to mine.
Life resists crit for spells (80+) and some spell damage.Try to have an open prefix for non chaos as extra chaos damage,but if you don't have it,its fine,remember we get up to 20% non chaos as extra chaos damage from EACH CHAIN,(gloomfang remember?) so that 9% craft is nice,but isn't our only source of extra chaos damage by all means.

Important suffixes are: Staunching (on an instant life flask) and Warding and Heat on a duration flask,Diamond for crit,and quicksilver for speed while mapping.
Atziri's is our only chaos resists for mines and general damage and Lavianga's solves any and all of our mana issues.
Until you are able to afford a lavianga's (early in the league it could cost10-15c) get a Catalyzed sanctified mana flask of (ANY SUFFIX YOU NEED) to assist with quick mana recovery.

Change depends on the situation,and if you need further clerification,I strongly recommend you to watch this pantheon guide I made to better cover the topic: https://youtu.be/Og5fTYe8xFs

We of course need 2 inevitibility jewels for the additional magma orb projectiles which leaves little room for other jewels,I picked double anger jewel with fire pen and crit multi watcher's eye and a life mana proj damage crit multi cobalt jewel.

Here I would prioritize fire pen while anger,the price on those is pretty cheap a couple of weeks into a leauge.
For a rare jewel,remember that our build has a lot of tags,I focused on getting nice defensive stats as well as some damage.