In the dimly lit lounge of credit scores, the three-digit number that lenders use to evaluate your risk as a borrower, it turns out that there are a lot of posers — and occasional brass knuckles.

Let’s just make it simple, shall we? The one you want is the studly FICO score, which comes from a formula created by a company called Fair Isaac. Ninety percent of lenders use the FICO in some way shape or form. You can get it here . We’re not paid to say that, it’s just easiest.

The problem - and it’s one that many people fluent in other areas of personal finance don’t even realize - is that there is more than one FICO score.

In fact, each of the big three agencies (Experian , Equifax and TransUnion ) produces their own FICO score, using a formula they license from Fair Isaac.

Another problem: When you apply for new credit or a loan or a job, you don’t know which one of the three scores the lender or employer will pull. So if you really want to know your credit score, you’re basically stuck buying all three FICO scores.

There are all sorts of ways to get confused and sidetracked here. For instance, some of the credit-reporting agencies sell their own proprietary scores, which we think are worthless. More on that in a sec.

But first off: Why should you care about your credit scores in the first place? If you’re applying for a loan, be it a mortgage for swank new digs or a private student loan (don’t forget to max out on federal loans first), having a high credit score can decrease your interest rate, potentially saving you thousands of dollars.

It would be nice to think that getting a FICO credit score directly from one of the three credit reporting agencies (Experian, Equifax and TransUnion) would be simple. But only Equifax will actually sell you its FICO credit score in a straightforward fashion (get it here ).

Beware what angry consumers call the FAKO scores like Experian’s PLUS score or TransUnion’s “TransRisk” score or the new Discover-Experian brainchild, the Credit ScoreTracker . These scores aren’t the same ones a lender would see when evaluating you, which makes them pretty much useless to you.

So why would the agencies want to produce them? When a consumer buys one of these faux scores, the credit bureau doesn’t have to fork over a slice of the profits to Fair Isaac for using Fair Isaac’s proprietary FICO formula. These FAKO’s look a fair bit like FICOs. That makes Fair Isaac mad. At least one lawsuit is between the various parties is brewing.

For your budget’s sake, just be sure that when you lay down the cash, you’re buying the right thing (again, that’s all three FICO scores from Fair Isaac’s MyFico site).

As for all of those credit-monitoring services MyFico and the credit-reporting agencies try to sell you? Pretty useless unless you really need day to day access to the ups and downs of your credit file. This may be the case if you’re in the heat of applying for a mortgage, have recently been a victim of identity theft or if you’re just really OCD about this sort of thing.

Think you’re OK buying credit scores in the one safe place to get your free credit report? We’ll, you’re not. That place is Annualcreditreport.com (they’re NOT the ones with the catchy jingle - these people are Equifax folks peddling the bogus scores). Once you get your free credit reports, the site will offer you links to the three bureaus’ homepages, where Experian and TransUnion peddle those bogus scores. Sigh.

Again, Equifax does make the real, true FICO score readily available. But TransUnion buries it in its site (we had to ask John Ulzheimer, the president of Credit.com, who spent years working inside Fair Isaac and Equifax, to dig up the URL after much failed Googling. Here it is. ) and Experian doesn’t at all. Instead, they peddle their FAKO products.

Experian’s Kelly Poffenberger claims that “there are many scoring models used in the marketplace” and “regardless of what scoring model is used, they all have one purpose: to summarize your creditworthiness.” But this doesn’t explain why someone would still want a FAKO over a FICO. TransUnion and Equifax didn’t respond to my repeated attempts to get a hold of them.

A sneaky consumer could try getting the 30-day free trial of credit-score monitoring then cancel before the monthly charges start hitting the credit card (since you’re required to ante up your card payment information first). But I think we told ourselves we’d do the same thing when dealing with all those Columbia House CD deals in the 90s.

We’re admittedly pissed that we have to pay in the first place , but we’re even more pissed that merely purchasing the score is a nightmare. The credit scoring system, which is supposed to make life easier for consumers and lenders, is nothing more than a barroom brawl between the credit-reporting agencies. As as result, consumers are getting caught in the hair-pulling and nail-scratching.

Put up your own fight accordingly.