A noun describing 'planned, intentional' betrayal, not limited to context of war

Question

Some weeks ago I found an English noun that is describing a kind of betrayal — namely, when Person 1 wants to betray Person 2, but Person 1 already knows he is going to betray Person 2 (he is going to do it at some time when Person 2 trusts him) before even building a relationship with Person 2.

I'm looking for another word for a 'planned betrayal'. A single noun.

Edit: It seems the word is 'perfidy' (https://en.wikipedia.org/wiki/Perfidy?wprov=sfla1) but only in war context — if it's not used in the context of war, then perfidy is an 'ordinary' betrayal (i.e. without the 'plan').

But is there a word that can also be used not in the context of war (with the 'war' meaning of perfidy)?

Example: Someone gets an animal, gains its trust, but with the intention of killing it. It could be called 'betrayal' but it's different from ordinary betrayal since there is the 'plan, intention'. However, I can't call this a 'perfidy' since the specific meaning of the word I want to use is used only in war context.

Answer 1

There are a lot of terms that mean to plan to to something bad, or likely bad, involving deceit; that seems to imply betrayal, but maybe it depends on how specific you are about what betrayal means. Otherwise, deceit, trick, con, etc., might work. The context in which some of these words are used might create the effect you intend.

A plan to steal by deception can be a con, a dwindle, etc.

Setup

something done by deceit or trickery in order to compromise or frame someone

https://www.merriam-webster.com/dictionary/setup

The betrayal was actually twice as deep because it had all been a setup.

In The Deal's Secret Heir. Kat Cantrell. https://books.google.com/books?id=AHfACwAAQBAJ&pg=PA144&lpg=PA144&dq=it+had+all+been+a+setup

plot

A plan made in secret by a group of people to do something illegal or harmful.

a secret plan or scheme to accomplish some purpose, especially a hostile, unlawful, or evil purpose: a plot to overthrow the government.

https://www.dictionary.com/browse/plot

Despite the definition' s use of group, one person can make a plot.

ruse

a plan or trick used for hiding your true intentions

https://www.macmillandictionary.com/dictionary/british/ruse

subterfuge

Subterfuge is a trick or a dishonest way of getting what you want. Most people can see right through that type of subterfuge.

https://www.collinsdictionary.com/amp/english/subterfuge

intrigue

the use of underhand machinations or deceitful stratagems.

https://www.dictionary.com/browse/intrigue?s=t

The intrigue was therefore one for placing a son of the French king on the Spanish throne.

https://sentence.yourdictionary.com/intrigue

And, as in your user name, there is a sting! A sting usually, or perhaps always, involves a group of people acting together to trick someone out of money. There is a very famous movie from 1973 about a sting: https://g.co/kgs/uozqZD

sting

us a carefully planned and complicated plan which deceives people so that criminals can steal something

A bank employee was involved in the sting in which $5 million was stolen.

https://dictionary.cambridge.org/dictionary/english/sting

Answer 2

I'd go for

to conspire, conspiracy

to collude in a group of people for secret enactment of a plan aiming for ones own gain at the expense of outsiders

this describes a group of people, as far as the criminal definition is concerned. A single person can nevertheless behave conspiritively. co- implies "tgether, with".

Legally, Ger Betrug (cog. "betray") in the criminal sense requires intent. An accidental betrayal is implausible. I'm not sure what the Common-wealth equivalent is. A spontanious decision does not change the fact, unless affective factors like fear that can cause benightedness come into play.

An animal is lured, tempted.

Given that you require preparation to be part of the definition, a word on pre-, pro- should work. One would be prey on; predation would be a little more elaborate, but roughly equivalent with hunt. Another legal term is premediation that isn't specific to betrayal, but chiefly negative due to the association with criminal codes.