Does it know its not the real person? 

Quote from Saberkatzero >>

Since the simulacrum is a construct created from a spell not a living creature with a soul it can simply be destroyed with a anti magic or dispel magic spell right?

 Does it not have a soul? I ask because there are constructs with souls. Warforge and Autognome.

Quote from VibranToucan >>

Does it know its not the real person? 

 I believe so.

Eh, have a forge cleric on hand (or just multiclass yourself) and you can make unlimited rubies out of just about anything with metal in it.

Fixed with one simple change of the final line.

Change "If you cast this spell again, any duplicate you created with this spell is instantly destroyed." into "If this spell is cast on a creature again, any duplicate created with this spell is instantly destroyed." And it doesn't work to casted it on the simulacrum since as previously stated, it's a construct (not a beast or humanoid).

This also solves the "Wish bypass" since the wish spell duplicates a spell of 8th level or lower. Duplicate. Meaning you're casting the the exact same spell with all it's benefits and all of it's restrictions included.

It's fun to theorycraft things as written and see how much you can break things, but if you're seriously considering using the loopholes to create a army of yourself... how much do you hate your DM and current campaign? ;)

Quote from Araldor_Brighthammer >>

Fixed with one simple change of the final line.

Change "If you cast this spell again, any duplicate you created with this spell is instantly destroyed." into "If this spell is cast on a creature again, any duplicate created with this spell is instantly destroyed." And it doesn't work to casted it on the simulacrum since as previously stated, it's a construct (not a beast or humanoid).

This also solves the "Wish bypass" since the wish spell duplicates a spell of 8th level or lower. Duplicate. Meaning you're casting the the exact same spell with all it's benefits and all of it's restrictions included.

It's fun to theorycraft things as written and see how much you can break things, but if you're seriously considering using the loopholes to create a army of yourself... how much do you hate your DM and current campaign? ;)

Actually, you don't need this addition. In RAW any pet, summon, etc you control counts as 'you' for the intent of casting spells and attuning items in situations such as this. So if a Simulacrum you created casts Simulacrum, it counts as you casting it, destroying the Simulacrum, arguably before it has a chance to finish the spell, since the wording implies that the newest duplicate stays alive and the oldest one is destroyed when you start casting the spell.

Quote from GrandMasterRadio >>

Quote from Saberkatzero >>

Since the simulacrum is a construct created from a spell not a living creature with a soul it can simply be destroyed with a anti magic or dispel magic spell right?

 Does it not have a soul? I ask because there are constructs with souls. Warforge and Autognome.

Quote from GrandMasterRadio >>

Quote from Saberkatzero >>

Since the simulacrum is a construct created from a spell not a living creature with a soul it can simply be destroyed with a anti magic or dispel magic spell right?

 Does it not have a soul? I ask because there are constructs with souls. Warforge and Autognome.

 It would not have a soul. As stated above, Simulacrums can be dispelled, so outside magic is what sustains them. Warforged, on the other hand, do not suffer any negative consequences from being targeted by dispel or entering anti-magic fields. The Warforge self sustain, meaning they have some form of soul that is driving their body, not just an arbitrary connection to the weave needed to move and keep them together.

So I have a question. If I cast simulacrum on a 20th level Barbarian will he have unlimited rages, all class features, all the feats, ability score improvements, and brutal critical but at half hp?

It persists according to Rime of the Frostmaiden.

I'm getting visions of Agent Smith in the 2nd and 3rd Matrix movies

does the simulacrum's type change to construct?

If the creature was benefiting from a buff at the time, like maybe someone had just cast heroes feast for them, would the simulacrum benefit from it?

Okay, we are currently Lv 14, and I’m playing an Eladrin Chronurgy Wizard 13/Cleric of Peace 1. I can add two (and swap out) tool or weapon proficiencies a day with my Trance feature; anything at all I would like to make, via Fabricate or whatever, with some actual quality to them—check.

My DM gave me the Tome of the Stilled Tongue ages ago, and I’ve been using that as my 1/day get-out-of-trouble card, as it allows me to Bonus Action cast *any* spell in the book subtly. This covers the missing slot for my Simulacrum, as I’d probably use the Tome to BA cast Wish to create it (once I can cast 9ths, obviously). No slots wasted. 

I have a Ring of Spell Storing as well, and use Arcane Abeyance a lot…

Any ideas on what more I could achieve with these features/items a normal wizard in my shoes couldn’t at this level? Without the DM beating me up, of course.

So have your Simulacrum spend time scribing all its spells as spell scrolls, whether it has the spell memorized or not. Instead of using the slots, it can just use the scrolls instead, then scribe the used scrolls again.  Sure, it's expensive and time consuming, but if you really want it to keep its utility at max, stocking it with spell scrolls keeps it at full power all the time. Plus, as long as it never casts, it can be a scroll scribe full time, churning them out for you at home while you go adventuring. It can do your spellbook copying and production, too, if you want to publish spellbooks.  

I would rule that it does not copy boosted stats due to magic items. Feats boosts would be copied, however.  Your Headband of Intellect will not get you a Simulacrum with a base score of 19 unless your base Int is already 19 (which case, why do you wear it?).  If you have a Belt of Giant Strength it would not get the boosted ability score, just the base. I know this is probably common sense, but it's not spelled out explicitly and some cheeselord will try to say otherwise and claim that casting Enhance Ability will get it to crazy stats. 

Quote from Leerjawise >>

if you are within touch range of a tarrasquefor 12 hours...

 Doesn't have to be a live

A Tarrasque is not a beast nor humanoid it is a monstrosity; therefore, it cannot be turned into a simulacrum.

- if i am a bladesinger wizard, and i cast simulacrum on myself , does the simulacrum copy have access to bladesong / bladesinger features ? -

Fix the loop.  The real original creature counts as the caster of any spell cast by a simulacrum. 

Quote from Colt45WKoch >>

So I have a question. If I cast simulacrum on a 20th level Barbarian will he have unlimited rages, all class features, all the feats, ability score improvements, and brutal critical but at half hp?

Quote from Alethalion >>

- if i am a bladesinger wizard, and i cast simulacrum on myself , does the simulacrum copy have access to bladesong / bladesinger features ? -

Yes, to both of these