Regulars to the Rippo experience will be aware of the more obvious failings that usually give them away.
To name a few:-
The month of manufacture can only be 'A' to 'L' on real Zippo's ('A' being January and 'L ' being December) On some Rippo's it is a 'U' or even a 'Z'.
The spelling of Bradford PA is often incorrect, sometimes showing 'Bradport PA' or 'Bradpord PA' and even 'Bradporo'.
Often date marks are shown in conjunction with a digital year of manufacture such as XVI/2001, which if you check your ID charts, you will find these dates and roman numerals conflict with each other. One of the roman numeral ID's on a lighter shown above is actually 'XYZ', almost funny in itself.
The process used to make the base stamp is often poor and lends itself to instant suspicion. Some bases appear stamped, but the chroming/finishing process can mask the lower quality stampings. Other fake base stamps are known to be created by acid etching, but by far the easiest to spot are the Engraved bases. Those looking to collect Vietnam period military Zippo's will find an awful lot of these engraved Rippo's cropping up on a regular basis.
On occasion you will find Rippo's with a deliberate spelling mistake in the name, Two examples are in the base pictures shown above, one being 'ZIPO' and the other being 'OPPIZ'. Some unscrupulous sellers have been known to try and convince buyers that this is a rare genuine Zippo with a mistake made on the base stamp. In case you need reassurance on this, IT IS NOT TRUE! they are Rippo's just like the rest. One of the lighters shown in the group above is even engraved with the place of manufacture showing as 'Vietnam'. It is also as fake as a fake can get. Maybe a talking point, but Rippo all the same.
Inners are another obvious giveaway, they often fail to fit well, and more often than not are easily spotted (if you are used to the real thing). There are a couple of pictures below to give you some idea of the difference. One last thing for this particular area:- The feel and sound of a genuine Zippo is quite distinctive, believe it or not, most Rippo's give themselves away as soon as they are opened.
There are differences in the build quality (hinge, rivet etc) that will stand out as fake to a collector, they are not necessarily easy for a newcomer to spot. That said, there are far better descriptions of these detailed differences in the forums and elsewhere on the internet.
One essential point to note:- All the above information relates to the more obvious Rippo's. Of late there have been some very good copies entering the public domain. These newer Rippo's are a very close likeness in appearance. Spelling mistakes are none existent, and date markings can look surprisingly genuine. It seems that the makers of Rippo's are upping the stakes. The Clone test page elsewhere on the site shows one of these more recent Rippo's in better detail.
Unfortunately, this change of Rippo manufacturing has come at the same time as Zippo's decision to modify their hinges. This could possibly lead to some confusion amongst casual collectors in the near future.