The Megaversal system, sometimes known as the Palladium system, is a set of mechanics specifically employed in most role-playing games published by Palladium Books, with the exception of Recon. It uses dice for roll-under percentile skill checks, roll-high combat checks and saving throws, and determination of damage (i.e. Mega Damage is to M.D.C. what "damage" is to S.D.C. ) sustained in melee encounters by which a character's Hit Points, Structural Damage Capacity (S.D.C.), or Mega-Damage Capacity (M.D.C.) is reduced accordingly.
Shannon Appelcline, in his book Designers & Dragons, states that the Megaversal system was a revamp of Palladium's AD&D-derived game system: "It was one part highly traditional – with its character classes, experience points and levels – and one part arcane – with its abbreviations like OCCs, RCCs, PCCs, PPE, SDC and MDC."
Certain aspects of character creation vary across series. Depending upon the game, players may or may not need to select a race; for instance, it is assumed that characters in Ninjas & Superspies are human, while in Palladium Fantasy they very often are not. Nonetheless, all games share the same eight randomly generated attributes:
- Intelligence Quotient (I.Q.)
- Mental Affinity (M.A.) – The character's personality and how well they can deal with others.
- Mental Endurance (M.E.) – The character's willpower.
- Physical Endurance (P.E.) – The character's basic level of toughness.
- Physical Prowess (P.P.) – The characters agility.
- Physical Strength (P.S.) – The character's strength.
- Physical Beauty (P.B.) – The character's physical attractiveness.
- Speed (Spd) – The character's running speed.
- Hit Points (H.P.)
For humans, most of these statistics are determined by a roll of three six-sided dice, whereas other species' attributes are determined more or less depending on how they compare to the baseline human standard.
Other statistics that may be used are:
- Structural Damage Capacity (S.D.C.) – Often supplements hit points; also functions alone as "hit points" of non-living objects.
- Mega Damage Capacity (M.D.C.) – In some cases in certain worlds will replace both S.D.C. and H.P. or supplement them
- Potential Psychic Energy (P.P.E.) – Energy commonly used for magic and other non-psychic supernatural abilities.
- Inner Strength Points (I.S.P.) – Energy used for psychic abilities and sometimes magic powers (Mechanoids, Phase World)
- Bio-Energy (Bio-E) – Used to design mutant animals
- Chi (no abbreviation) – Energy used for chi powers in Ninjas & Superspies.
- Force Points (FP) – Energy used for Force Field and Create Force Constructs in Heroes Unlimited
- Power Touch Points (PTP) – Energy used for Power Touch in Powers Unlimited
The characters' race and attributes – not to mention the game itself – impact their selection of character classes:
- Occupational Character Classes (O.C.C.) – Skills and abilities based on training.
- Psychic Character Classes (P.C.C.) – Focus on psychic powers.
- Racial Character Classes (R.C.C.) – Abilities and skills which are primarily a function of race, or are limited to members of a certain race.
Depending upon the game, skills can come either from the character's O.C.C. and a related list, or from the character's educational or occupational background. Games set on modern Earth tend to favor the second; all others favor the first. O.C.C.s tend to be more specific than character classes in other games, with a wide range of O.C.C.s in a given profession, such as six or seven specialized mecha pilot classes in Rifts rather than a single "Robot/Power Armor Pilot" class.
Palladium's alignments are described in detailed terms, outlining how a character will act in a certain situation: whether they will lie, how much force they will use against innocents, how they view the law, and so forth. The alignments are organized into three broad categories: Good, Selfish, and Evil. The seven core alignments are:
- Principled (Good)
- Scrupulous (Good)
- Unprincipled (Selfish and also good)
- Anarchist (Selfish)
- Miscreant (Evil)
- Aberrant (Evil)
- Diabolic (Evil)
An eighth overall (and third Good) alignment, "Taoist", was introduced for Mystic China, but has not seen use outside of that game.
Palladium founder and lead designer Kevin Siembieda has a noted distaste for "neutral" alignments (as used in Dungeons & Dragons). This is stated in most core rulebooks in the alignment section, and stems from the idea that a truly neutral character would not do anything particularly interesting, like fight or go on an adventure.
Other system variations
Each game has its own variations to make the system better suit its genre. After the Bomb, Splicers, Heroes Unlimited (for mutant animals only), and Teenage Mutant Ninja Turtles & Other Strangeness use "Biological Energy" (BIO-E) points to purchase mutations. Palladium Fantasy assumes that non-human characters will be routinely played, so most races will use normal O.C.C.s instead of R.C.C.s.
Some games that feature advanced technology in science fiction settings like Rifts, Robotech, and Splicers use a special category of damage capacity called "Mega-Damage" (M.D.C.); the exception is Mechanoids. M.D.C. is 100 times more powerful than normal damage (i.e., 1 M.D.C. = 100–199 S.D.C.). Normal weapons cannot damage a Mega-Damage structure at all unless they are capable of inflicting 100 S.D.C. or more in a single shot or burst of ammunition; the archetypal example of Mega-Damage is a tank, which can only be effectively destroyed through the use of powerful weapons designed to overcome its armor, while easily resisting small-arms fire. Many updates to the system in various campaign settings have also added Perception as a statistic. Prior to this it was entirely up to the GM if the player noticed anything.