Imitations of original products are a problem in the business culture. It results in lawsuits both by the companies of the original product and those who bought the fakes in the first place. Perhaps they were used with cheaper or low-quality materials or have functions and apps excluded from the original.
But just because something is an imitation doesn't mean it can't be just as good. In fact, it may be just as effective if not better in some areas. The main advantage mainly focuses on mass-production since they can be produced more cheaply or with materials on-hand. Even if they're not 100% as effective, the fact they're 75% or even half as effective is still better than current technology, which can be why customers wouldn't mind in the first place.
Contrast the Shoddy Knockoff Product, which is expected to be defective imitations nowhere near as good.
- Bakemonogatari: In the Nisemonogatari subplot, the Central Theme that surrounds the story is whether or not a "fake" can be more real than the real thing. Examples of this include Tsukihi, who turns out to be not blood-related to Koyomi, but who is still his precious sister in his eyes and Kaiki Deishuu, a conman pretending to be a Blue-Collar Warlock, who actually manages to solve a supernatural case using his guile.
- In Fullmetal Alchemist, the Starter Villain Father Cornello is given a fake Philosopher's Stone to attract mindless followers into his religious order. However, it follows the same effects such as the apparent violation of Equivalent Exchange that it fools the Elric brothers into mistaking it for the real thing.
- The GN Tau Drives in Gundam 00, respectively named "pseudo-reactors" by the original creators, are only slightly less effective than the actual solar reactors. Yet, they can be mass-produced and allow Earth's nations to compete against the Gundams. The manuals explain that the Tau Drives have everything except the TD Blankets, which can be only made with materials from Jupiter and is part of a production process that takes up to a full year to make.
- Transformers: Age of Extinction combines this with Gone Horribly Right. The human-built Transformer Galvatron was built to be exactly like Megatron. And...he is exactly like Megatron.
- The Dresden Files: Death Masks features the Shroud of Turin as a central MacGuffin with potent healing powers. Much later in Skin Game it's revealed that Jesus's actual burial shroud is somewhere else, and that the Shroudof Turin is a forgery that ended up developing the same powers as the original because so many people believed in it.
- Part of The Reveal in The Fifth Elephant is that the Dwarf relic, the Scone of Stone was not stolen, but destroyed and that the supposed thieves are holding a replica instead. This trope comes into play when it's revealed that the Scone has been destroyed and replaced with multiple replicas already, as Dwarf bread doesn't last forever. The one recovered from the supposed thieves proves a suitably accurate replacement.
- The Moon Is a Harsh Mistress: The guards of the Lunar Authority have laser guns. Chinese engineers are tasked with creating knockoffs of their laser weapons to arm members of the revolutionary forces. When the Rebellion begins, the copied laser weapons are used against the Lunar Authority's forces.
- In The Tamuli the protagonists are given quarters in a replica of a castle - the empire in the book houses visiting diplomats in replicas of buildings from their own cultures architecture as a way of making them feel at home. As one character notes, the slavish way in which the replica was constructed meant they'd included many of the castles defensive features without even realizing they were there. This comes in handy later on when an armed rebellion against the empire kicks off.
- Warhammer 40K. Ork technology is either looted from enemies or built in vague imitation of their weapons (especially bolters). It annoys and horrifies the Adeptus Mechanicus to no end that such arms built with no respect for the techno-theological rules can often surpass their own wargear.
- Assassin's Creed Origins has the "Imitation Siwan sword", a Cursed with Awesome sword that does triple damage as well as multiplying your critical hit chances but also caps your maximum health to one-third of your normal maximum. Your protagonist immediately spots it for the unconvincing fake it is and puts on a show of being duped by it... because the little girl whose mother sells it to you is...adorable?
- The Excalipoor in Final Fantasy V is a crappy knockoff of the Excalibur, and a Joke Item that only does 1 damage for regular attacks. But if you throw the knockoff onto an enemy or use it for the Goblin Punch special ability, it can carry a whooping amount of damage. Additionally, its basic attack is an Always Accurate Attack, which can be exploited by using the Spell Blade ability to imbue it with status effects, even instant death.
- In Sonic Adventure 2, Tails creates a fake Chaos Emerald. He plans to have Sonic give it to Dr. Eggman, after which it would destroy the Eclipse Cannon after he used it in place of the real one. Eggman catches on because he notices two energy readings of Chaos Emeralds, but it turns out that because it's such a good copy, Sonic can use the Chaos Control ability with it just as if it were the real thing.
- Xenosaga: A Cosmic Keystone, known as the (original) Zohar, is a source of practically unlimited power. There are also several artificial constructs known as imitation Zohars, and while none of them even come close to the frightening omnipotence of the original, each one of them is a MacGuffin that grants great amounts of power to its wielder.
- Mega Man Zero: Zero himself is revealed to be a "knockoff" of Omega, the Final Boss. Despite that, Zero cares little about it and just proceeds to defeat Omega (when no other people have done before). The more impressive thing is that Omega's body was once Zero's; Zero is simply badass enough to defeat his own (more powerful, not to mention boosted) body.
- Warcraft III: Abilities come in three varieties: hero (get stronger with level but only used by heroes), normal (single-level abilities used by regular units) and items (which are mostly the same as the normal spells, but cast by using the item).
- Item versions of spells are weaker than the heroic versions, but are by no means ineffective, since the spell's effect rather than its area of effect, damage or duration is the important aspect. Additionally, they usually cost no mana to cast.
- Normal spells cost mana to use, but in some cases are more effective than the faction-unique version. For example, every faction's caster has three spells, requiring two levels of training, themselves only available after upgrading the main base twice, but some mercenaries have the ability available as soon as they're hired, leaving only the question of whether the caster or the merc is the more cost-effective unit.
- BlazBlue: Iron Tager's cyborg enhancement is described as "Artificial Causality Phenomenon Weapon", and Lambda-11's (and later Ragna's) Idea Engine is its improved version. Despite being powered by advanced (but still traditional) mechanics instead of souls, its capabilities rival that of proper Causality Phenomenon Weapons, i.e Nox Nyctores. There's also Celica's Ex Machina: Minerva, an automaton guardian made by Prof. Kokonoe (who's behind Tager's and Lambda's enhancements) as an imitation to Nox Nyctores Deus Machina: Nirvana (owned by Carl) and manages to be crazier (gameplay wise) than Nirvana does.
- The Unlimited Blade Works in Fate/stay night is all about creating an unlimited arsenal of Noble Phantasms that are knockoffs. Shirou states that they can not defeat the original Noble Phantasms, but are still able to imitate their abilities to a close second. Gilgamesh is defeated by this Noble Phantasm because even though he has all the originals, he merely uses them as throwing objects, never utilizing them to their full potential.
- That, and being copies, they can be broken, turning them into a single use version with a rank boost that bumps the power up to the same as the original. Since it's a copy you can always just make another one after breaking the first.
- False Caster from Fate/strange fake creates false Noble Phantasms that work even better than the originals. Personally, he advocates for this trope, demanding his boss hire some mage he's heard about who can create dozens of imitation Noble Phantasms at once.
- In Schlock Mercenary, Schlock starts requisitioning knockoff BH-209 Plasguns from the ship's fabber after Strohl Munitions discontinues the model. They're about as prone to exploding as the original.
- Volpina from Miraculous Ladybug is an Evil Knockoff of users of the fox miraculous created by Hawk Moth using the power of the butterfly miraculous. She has all of the same powers that the fox miraculous bestows, but she is able to create as many illusions as she wants. This is in contrast to Rene Rouge, the real owner of the Fox Miraculous, whose special power "Mirage" allows her to create one illusion before needing to recharge.