Simulacrum, is potentially the most abusive spell in the game. Giving you an extra PC.
The down sides are
*1500 cost, preventing you from spamming it. (It's cheaper to heal an old one)
*100 to regain a hit point (i'm going with the less abusive interpritation where it otherwise doesn't heal).
*Can't regain spell slots.
*Doesn't level (this isn't too bad).
*No equipment (not usually too bad, considering the cost of the spell).
*Casting it again destryos the first.
Thus you want someone who...
1: Won't get hurt. (ranged).
2: Doen't rely on spells slots.
Bow Fighter: Highest at-will damage in the game. Melee can't depend on hit points or second wind to survive.
Rogue Safest character, with plenty of defensive features (like hiding behind walls after attacks) means you can keep it a long time if your careful. Less damage then the fighter, but still good.
Warlock: Strong at-will damage with good at-will utility. Sitting somewhere between rogues and fighters. Bladelocks are decidedly worse.
Bow Ranger: Strong ranged damage makes this a solid choice. Though it's spell slot reliance keeps it from being top. Beastmaster arn't bad, since the beast you train can heal. Melee, is worse. Though even if you copy a TWF ranger, they can still shoot bows.
Bard: Insperation per short rest is solid. Bow Valor works better with it's at-will damage.
Cleric: Channel divinity can be recharged, and they have either weapon or cantrip damage boost and come with good AC. Just make sure they are ranged.
Moon Druid: Wild Shape gives you a way to recharge your HP, though since it's melee, it's limited. Land are decidedly worse.
Monk: Dispite being melee, with high speed you can get in an out of melee without being hurt while delivinging stuns. Plus several other defensive measures like deflect arrows and evasion, they can stay alive a good time. And they can fall back to d10 slings with 2 attacks. And a small bonus of not needing equipment.
Paladin Lay on hands, channel divinity, and a good number of defensive features. Just don't let him go into melee. Not bad for someone who's supposed to work in melee with spell slots.
Sorcerer's: Dispite being spell slot depenant, you can fling off quickend or twinned firebolts to reasonable effect.
Simulacrums for profit.
1: Get Simulacrum, and Wish (level Wizard 17, Sorcerer 17, or bard 17/18 depending on weather you can retrain magic secrets).
2: Take a long Rest
3: Cast Simulacrum on yourself (1,500 gold)
4: Have your Simulacrum cast Wish, gaining treausure (25,000 gold).
Your simulacrum will suffer any downside of casting wish.
5: Profit (23,500 every day).
You can risk your simulacrum on other things, like wishing for magic items, resurecting disintigrted people, ect... Note that you can combine this with other tricks.
Infinite Simulacrums.
1: Get Simulacrum, and Wish (level Wizard 17, Sorcerer 17, or bard 17/18 depending on weather you can retrain magic secrets).
2: Take a long Rest
3: Cast Simulacrum on yourself.
4: Have your Simulacrum cast Wish, duplicating the effect of Simulacrum.
The simulacrum is not destroyed since "you" didn't cast it.
The newest copy still has a level 9 slot avaibile.
5: Order the the old simulacrum to tell the new simulacrum to be friendly to you and take oders from you.
6: Repeat 4-5 ad-nausium.
A potential downside is that the simulacrums don't directly take orders from you. So some devious DM's might disguise a NPC as you and order your simulacrums, taking advantage of the confusion.
Simulacrum + Inspiring Leader / (True) Polymorph / Magic Jar.
Each will give your simulacrum a some extra HP to burn. He still can't regain any, but it goes a long way to keeping it alive.
(again, going with the less abusive interpritation where the ability to not heal is not a "game statistic".)
Thoughts?
Illusionist Wizards are likely the top Simulacrum users, thanks to Malleable Illusions. That feature lets you change the clone's form to that of another valid target at any time as an acion, making the spell far more versatile than it already is. Also, pending on interpretation, this allows the clone to effectively regain spells, HP, and other limited-use features.
Also, Wizard clones with Magic Jar can be amazing. When they possess a different body, they no longer suffer from Simulacrum's negative effects (ie no regained spells or HP), since they keep only their class features and mental ability scores when possessing someone else. There are some risks involved: the clone would not be automatically friendly to you in that state, and it would be highly vulnerable to a stray Dispel Magic. But I guess if you don't treat the clone too badly, it shouldn't have a reason to not help you out otherwise... (Sorry, can't remember the name of the person who revealed this trick)
mellored wrote:
ShinQuickMan wrote:
mellored wrote:
Llenlleawg wrote:
Simulacrum + True Polymorph.
Turn each simulacrum into a CR 20 Adult Gold Dragon (and give said dragon the spellcasting and other templates which don't increase CR).
Each simulacrum dragon is now more powerful than your typical level 20 PC, can heal naturally, can fly, can deal massive AoE damage, can cast some spells, has legendary actions, legendary resistance, and a boatload of HP. You can also give the dragon magical gear such as rings of protection, ioun stones, etc.
This combos nicely with infinite simulacrum.
Lawolf wrote:
mellored wrote:
Nice metagaming abuse mode.
Of course it's even worse as the profit on the first example is actually 23,500 gold per day...
But then you can't profit from what any decent DM will ban-hammer on the basis of metagaming and/or lack of rubies from all the mines playing out during the the 1st Age Clone Wars... 
mellored wrote:
Of course it's even worse as the profit on the first example is actually 23,500 gold per day...