Guide:Thrileon's Guide to Double alchemy crafts

In this guide i will show how you can get 99.75% chance to craft x2 potions per craft on alchemy.[edit | edit source]

We need level 10 character to get there. But we have good chances before that. (Sorry for my English, English is not my native language)

First we need the character. i prefer to use hireling because this character will stay in camp is not going to fight. so step by step. i will show you the important choises and then ill explain everything.

Level 1 - Wizard lvl 1 - 16 wisdom + medicine proficiency
Level 2 - Wizard lvl 2 - Subclass Trasmutation
Level 3 - Cleric lvl 1 - Guidance cantrip
Level 4 - Cleric lvl 2 -
Level 5 - Cleric lvl 3 - Spell : Encance Ability
Level 6 - Cleric lvl 4 - Feat -> Ability Improvement -> +2 Wisdom
Level 7 - Bard lvl 1 -
Level 8 - Bard lvl 2 -
Level 9 - Bard lvl 3 - Expertice Medicine
Level 10 - Bard lvl 4 - Feat -> Ability Improvement -> +2 Wisdom

How it works. The wizard - Trasmutation school at level 2 gets Experimental Alchemy (subclass Feature) where You can brew two alchemical solutions instead of one when combining extracts, if you succeed a DC 15 Medicine Check (Wisdom). Then we increase our Dice bonus from other subclasses to increase our chances to success to 99.75% at lvl 10.

We start with 2 level on wizard to get the Experimental Alchemy. At this point we have 55% success chance.
Because 15dc (+2 medicine proficiency +3 wisdom) -> 1D20 = We need 10 or more on dice.

Now we Multiclass to get 4 levels with Cleric.
From first level of Cleric we get Guidance. That will give us 1D4 bonus on roll at craft for now.
From level 3 Cleric we get Enhance Ability spell. We buff our self Enhance Ability -> Owl's Wisdom to get advantage every time we craft with alchemy. From now on we don't use guidance with this toon only Owl's Wisdom because both are concentration spells and advantage is much better than 1d4. (if you have some other toon to give guidance to crafter is welcome).
From level 4 cleric select FEAT -> Ability Improvement -> +2 wisdom.
At this point we have +3 from medicine + 4 from wisdom + advantage. So we need to hit 8+ with one of the two dices. (+ 1d4 guidance from another toon?).

Now we multiclass again to get 4 levels with Bard.
First two levels don't have anything important
But at 3rd level of bard we select Expertice Medicine. To increase more our bonus to roll.
At level 4 Bard we select FEAT -> Ability Improvement -> +2 wisdom.
And this is it.

You should have +5 from Wisdom +8 from medicine and advantage on roll from Owl's Wisdom.
13 bonus is enough because is DC 15. If we hit 1 is critical fail... so even if you have +15 bonus you fail. So 13 we have from bonus +2 from dice = 15.
Because more bonuses are useless the only useful thing is advantage we get from Owl's Wisdom. Advantage means we throw two dices instead of one and we use the higher number. So the only way to fail is to hit 1 with 2D20... this is like 0.25% chance to happen....

An other build available : Using a halfing (hireling avaible) for the halfing luck feature (reroll 1 on ability check)

Level 1 - Wizard lvl 1 - 16 wisdom + medicine proficiency
Level 2 - Wizard lvl 2 - Subclass Trasmutation (57,75% success chance)
Level 3 - Rogue lvl 1 - Expertice Medecine ( 68,25% success chance)
Level 4 - Wizard lvl 3 -
Level 5 - wizard lvl 4 - Feat -> ability improvement -> +2 Wisdom (84% success chance)
Level 6 - Rogue lvl 2 -
Level 7 - Rogue lvl 3 -
Level 8 - Rogue lvl 4 - Feat -> ability improvement -> +2 Wisdom (89,25% success chance)
Level 9 - Any class - Bonus proficiency ( 99,75% success chance)

Success chance
Build	lvl 1	lvl 2	lvl 3	lvl 4	lvl 5	lvl 6	lvl 7	lvl 8	lvl 9	lvl 10
First build		55	67,5	67,5	84	87,75	87,75	87,75	99	99,75
Second Build		57,75	68,25	68,25	84	84	84	89,25	99,75	99,75

Both succcess rate can be improved further with someone casting guidance (lvl 5 and above for build 1, at all level for build 2). To get the best success rate, select a halfling hireling, follow the second build for level 2/3/4, then respec to the first build for level 6/7 and respec at level 8 for the second build. You can also hire two hireling to cast Enhance Ability + guidance at level 3.

Brief idea: Gith astral knowledge ability wisdom would be an added buff to consider here, as well. Grants proficiency in Animal Handling, Insight, Medicine, Perception, and Survival. There is a gith monk hireling you can respec using withers, I make it a Wiz2 Cleric whatever and double potions like a boss. I prefer the higher cleric level for my 3 hirelings as they run Warding Bond, prot poison, death ward, daylight and Aid (Highest level remaining to cast) full time on 3 of my characters. I use Karlach as a life tank and the paired warding bond rings available in Moonrise tower graveyard for Shadowheart. Really cuts down on rests. Essentially makes every character a barbarian with heart of the bear with regard to damage. Proficiencies are not supposed to stack*, but by lvl 8 it seems like 100% not 87.75% on doubling - but perhaps that save game reflex is the cause? *Once you know how to swing a hammer, you know how to swing a hammer, until you gain expertise with that hammer!