http://depthome.brooklyn.cuny.edu/classics/gladiatr/types.htm#note%203
The provocatores are distinguishable by a helmet without crest, a curved rectangular shield, and a sword with a straight blade. In addition, the provocator was the only gladiator to have effective protection for the upper body: a rectangular breastplate (as can be seen on the figure on the far right in the middle panel of this relief). The provocator thus lacked what was a badge of honor for other heavily-armed gladiators: a naked torso. Junkelmann explains: "It was in the very nature of the gladiatorial system that fighters were ready to die, and demonstrated that readiness by baring their torsos. If the fighters had been entirely unprotected, the outcome would have been either a brief, unskilled bloodbath or an excessively cautious, boring fighting style. The juxtaposition of armed and unarmed parts of the body controlled the use of weapons and created the conditions for dynamic and skilful swordsmanship. Nor must we forget the visual stimulation of seeing muscular bodies in vigorous exertion, defying death and injury."
http://www.unrv.com/culture/roman-gladiators.php
Provocatores(challengers): Paired against the Samnites but their armament is unknown and may have been variable depending on the games.
http://www.roman-empire.net/articles/article-013.html
Provocator: substantially analogous categories, that were used against the retiarius. The armament is generally analogous to that of the myrmillo, except for the ovoidal helmet, devoid of crest, so that it could not get caught in the net.
http://www.ukans.edu/history/index/europe/ancient_rome/E/Roman/Texts/secondary/
SMIGRA*/Gladiatores.html
Provocatores fought with the Samnites (Cic. pro Sext. 64), but we do not know any thing respecting them except their name. They are mentioned in inscriptions (Orelli, 2566). The proboka/twr mentioned by Artemiodorus (ii.32) appears to be the same as the provocator
http://www.alphaminiatures.co.nz/p_irw_gladiators.htm
Provocator's were medium gladiators and usually fought each other. They were armoured with a visored helmet, a breastplate, a half-length greave on their left leg and padding on their right arm.
http://ancienthistory.about.com/cs/games/a/gladiatorweapon.htm
There were many types of gladiators in ancient Rome. Some gladiators -- like the SAMNITE -- were named for opponents of the Romans; other types of gladiator, like the PROVOCATOR and SECUTOR, took their names from their functions: challenger and pursuer.
Provocator was armed like the Samnite with a parma and a hasta, his opponent was often the Myrmillo
http://www.pbs.org/wnet/warriorchallenge/gladiators/profile_job.html
Provocator (only gladiator to wear a full breastplate of armor
http://www.geocities.com/Athens/Olympus/3296/gladiators.htm
PROVOCATOR: The term "provocator" is Latin for "challenger" and reflects the function of this class. The Provocator was a popular opponent for both the Myrmillo as well as several less favoured classes of gladiator. Armoured after the Samnite fashion he used a round shield (parma) and a lance (hasta).
http://www.gladiator.hu/classes.htm
PROVOCATOR: His equipment and fighting style is unknown, although the name of the branch is quite expressive
http://www.ludus.org.uk/r/essayprovocator.html
Provocator Author: Graham Ashford 2001
The Provocator generally fought gladiators of their own type. Distinctly armed in comparison to other scutarii they fought with the scutum (occasionally shorter than most but not as short as the thraex parmala), a gladius or other short sword. They wore normal armour on the sword arm and shield leg (manica and greave, although of varying types and sizes). Their helmets and chest armour though is what makes them quite unique among the scutarii contemporary to them.
Originally the helmets they wore took the Gallic style worn by contemporary Roman Soldiers, in time this helmet changed considerably to a large dome shape with heavy neck flares (although this may just be artistic interpretation of the Gallic helm), however for main part of the period the Provocators existed they appear to have fought using the gallic helm with or without a face guard. Covering the top portion of their chest they, wore a piece or armour which sometimes managed to cover the top of the shoulders at least past the clavical called a pectorales. In the best example of these gladiators the frieze shows their front and back allowing us to see a way that the armour would have been fixed, by a leather cross piece or through from the sides of the armour piece and onto an iron ring placed in between the shoulder blades.
In no depictions (I am aware of) do the Provocatores fight anyone but their own type. This may be due to the light chest armour they are depicted wearing which may well have given them too greater advantage over their opponent, but as we have seen in other gladiator types at the absence of one form to fight another is found, it would stand to reason that the other fighter in such cases would have been either a similar type such as a Myrmillo or an opponent found fighting scutarii such as a thraex.
Little else is known of the Provocator other than the fact that they are seen in reliefs as early as 30-10BC and in tombstones as late as the 3rd Century AD, in each case the only pieces that appear to have changed in their equipment is the shape of the helm and the chest plate which started square but ended crescent shaped in the late Imperial Age. It would appear that although there is little known about them as a fighting type they enjoyed longevity in the arena, perhaps because of their closeness to the look of the Roman Soldier?
In our experimentation is would seem that in single combat the strength of the Provocator as with most scutarii, lies in defensive play under the cover of the huge shield, striking into the opponents side and flanks when they over extend themselves in an assault. Should an attack have to be made they are almost usually always lead with either a shield bash or as I prefer (portraying the Provocator) with slashing feints with the gladius hiding behind the scutum for cover until an opening is made for a fatal thrust.
http://hrsbstaff.ednet.ns.ca/waymac/History%20A/A%20Term%201/1.%20Rome/
origins_of_the_gladiators_student_version.htm
There were, however, two gladiatorial categories of gladiators that only fought opponents of the same type: the eques ('horseman') and the provocator ('challenger').
The provocatores are distinguishable by a helmet without crest, a curved rectangular shield, and a sword with a straight blade. In addition, the provocator was the only gladiator to have effective protection for the upper body: a rectangular breastplate (as can be seen on the figure 2nd row above). The provocator thus lacked what was a badge of honor for other heavily-armed gladiators: a naked torso.
http://roma-victor.com/community/bb/viewtopic.php?t=1167
Provocator - Unlike most of the gladiator types, provocators only fought other provocators. Like most heavily-armed gladiators, the provocator probably carried a scutum and gladius. He wore an uncrested helmet, along with a rectangular breastplate that protected his upper body, unlike most other gladiators. This actually showed that he was lacking in honor, as most gladiators liked to prove they were ready to give up their lives by leaving their torsos unarmored.
*red notes: everyone else thinks that they used the curved square scutum.