Big Eyes, Small Mouth (a.k.a. BESM) first appeared in August of 1997, billing it self as the anime role-playing game. Approximately six months later, it was nominated for an Origins Award for "Best New Role-playing System." In December of 1998 the first BESM licensed product was released, The Sailor Moon RPG And Resource Book. The game engine was now known as the "Tri-Stat System" and the company responsible was Guardians of Order, Inc. In July of 2000, the second edition of BESM was released, in which material from the original BESM rulebook was reworked, rewritten, and expanded on, incorporating material from such companion supplements as Big Robots, Cool Starships, and Hot Rods & Gun Bunnies.

BESM has now become a generic gaming engine, much like HERO System or GURPS. Aside from multiple anime related sourcebooks (Sailor Moon, Tenchi Muyo!, El Hazard to name just a few), GoO has also released a sourcebook for the film Ghost Dog: Way of the Samurai, and is releasing the Second Edition of Hong Kong Action Theater! (a.k.a. HKAT!). Many of these sourcebooks contain interesting and useful characters, and the Tenchi Muyo! sourcebook has to be one of the best-looking rulebooks to ever be released (it is just gorgeous to look at).

The following is a rough guide to converting from Big Eyes, Small Mouth to HERO System. Note that due to the nature of BESM, character abilities are somewhat more abstracted than in a system such as HERO or GURPS, so derived results are not absolutes, and are subjective to the wishes and desires of the person doing the translation. These conversion notes are based on BESM Second Edition, and the author recommends that anyone doing any BESM to HERO conversions have a copy of BESM Second Edition handy.

Note! This conversion information is only valid for people characters, not mecha. Mecha notes will have to wait until The Ultimate Vehicle is released.


BESM presumes that a normal human has a 4 in all three stats (BODY, MIND, SOUL). These three stats then are used to figure the stats of Health Points, Energy Points, Shock Value, and Combat Value.

STR	BODY x 2.5 and see "Super Strength" below.
DEX	BODY x 2.5
CON	BODY x 2.5 (or Shock Value x 1.25)
BODY	HEALTH/4 but see "Damn Healthy!" below.
INT	MIND x 2.5
EGO	SOUL x 2.5
PRE	([MIND + SOUL])/2 x 2.5
COM	See "Appearance" below.
PD	Figured x 2 and/or BODY.
ED	Figured x 2 and/or BODY
SPD	Figured but see below.
REC	Figured
END	ENERGY/2 and see "Energy Bonus" below.

Level 1: 25 STR (note: this value suffers from a minor problem, a BODY of 10 equals a 25 STR, a BODY of 11 = 28 STR, a BODY of 12 = 30 STR)
Level 2: 35 STR
Level 3: 45 STR
Level 4: 58 STR
Level 5: 63 STR
Level 6: 80 STR

A base character in BESM has 40 HEALTH. Divide by 4 and one gets a HERO BODY score of 10. This formula falls apart quickly, as some BESM characters have HEALTH scores of 115 (or more). There are several works around for this:

  1. Everyone has 10 BODY base. Each level of Damn Healthy adds 2.5 BODY to max of 6 levels or +15 BODY.
  2. Use this formula: 20 HEALTH = 5 BODY, 40 HEALTH = 10 BODY, 60 HEALTH = 13 BODY, 80 HEALTH = 15, 120 HEALTH = 18, 160 HEALTH = 20 BODY (and so on).

Level 1: 12-14 COM
Level 2: 14-16 COM
Level 3: 16-20 COM
Level 4: 20-24 COM
Level 5: 24-26 COM
Level 6: 26-30 COM

Each level of Energy Bonus gives +5 END (max of six levels or +30 END).


This is a very subjective stat. The BESM game scale for combat works out like this:
A combat round is 1-10 seconds. For convenience there are presumed to be 15 rounds per minute. Thus, 1 round is about 4 seconds. This means that a character gets 3 actions per 12 seconds (one HERO System Turn), meaning that all BESM characters have a base SPD of 3. However Extra Attacks can increase the number of attacks per round up to 6 extra attacks per round (for a total of 7 attacks per round). This comes out to 105 attacks per minute (7 x 15) which is somewhat beyond the Hero maximum of 60 (12 SPD x 5 12 second Turns). A direct Extra Attacks to SPD correlation is beyond me. If we pretend that Extra Attacks 6 = a 12 SPD, and a base character has a 3 SPD, that leaves 5 levels of Extra Attack to divide among 8 SPD slots. We get this:

Base: 3 SPD
Level 1: 4 SPD
Level 2: 5 SPD
Level 3: 6 SPD
Level 4: 8 SPD
Level 5: 10 SPD
Level 6: 12 SPD

Naturally, this is very subjective, and probably not very accurate. Note that in many cases the Extra Attacks being used in BESM might be lumped into one attack in HERO (via Autofire or some such mechanic).


BESM states that a character can run at BODY x 5 meters per turn. Thus, a normal human can run 20 meters in 3-5 seconds. If we pretend that a round is 4 seconds, we get 60 meters every 12 seconds. A SPD 2 normal runs 48 meters in 12 seconds (6" Running x 2 Non-combat x 2 Phases x 2 for inches to meters). A SPD 3 Hero character runs 72 meters. This means that basically, we can figure a character's running as [BODY x 5]/2 to get HERO inches of Running. The only drawback is that any strong character is automatically a fast runner.

Movement is also altered by such things as the Speed Special Attribute. In this case, look at the kph of the attribute and convert from there based on the character's speed. For example a base normal with a BODY of 4 and 1 level of Speed can run at BODY [i.e. 4] x 7 kph an hour, or 28 kph. This is about 45" per HERO Turn. If we presume the base SPD of 3, then this comes to 45/3 = 15" noncombat, or 8" per Phase. The same formula can be used for Flight or Swimming.

Note that based on this conversion, one may not want to alter a BESM character's Running from the HERO System default of 6", unless they have the Speed Attribute.

For Swimming, a BESM character can swim at BODY x 1 meters per round. For a baseline human, this is 4 meters per round, or 12 meters per 12 seconds. In Hero, a baseline normal can swim at 8 meters per Turn (2" x 2 Noncombat x 2 Phases), and a three SPD character can swim at 12 meters. This matches up fairly well, and shouldn't altered unless the character has the Swimming Attribute.

On a final note concerning Movement, BESM states that if a character that can move at X kph out of combat, then they move at that same value in meters per round in combat. For example: if a character can fly at 75 kph, they move at 75 meters per round. This can help determine over all Flight speed and Noncombat multiples when translating to Hero.


Damage in BESM breaks down in 5 point increments (usually). For example, a pistol does 5 points of damage, a katana does 10, and so on. This damage is modified by the character's Combat Value (it is added to the result) and any special attributes and/or skills the character may have. Note that a character's Combat Value increases the damage from both Hand-to-Hand and Ranged attacks.

A rough conversion of BESM damage to HERO System is as follows:

5 Points = Light Pistol = ~1d6 RKA (3-4 Damage Classes)
10 Points = Heavy Pistol/Katana = ~1 1/2d6 - 2d6 RKA (5-6 Damage Classes)
15 Points = Assault Rifle/Light Machine Gun/Huge Sword = 2d6+1 - 2 1/2d6 RKA (7-8 Damage Classes)
30 Points = Heavy Machine Gun = 3d6 - 3d6+1 RKA (9-10 Damage Classes)
45 Points = Light Autocannon = 3 1/2d6 - 4d6 RKA (11-12 Damage Classes)
60 Points = Medium Tank Gun or Anti-Tank Rocket = 5d6 RKA (15 Damage Classes)
75 Points = Heavy Tank Gun = 6d6 RKA (18 Damage Classes)
90 Points = Battleship Main Gun = 8d6 RKA+ (21+ Damage Classes)

As an example, Ryoko (from the Tenchi Muyo! sourcebook) can do 60 points of damage with her beam sword. This equals about 5d6 of Hand Killing Attack. If we take her 30 STR into consideration, this means her beam sword is about 3d6 HKA base.

Let's compare these numbers to the values for the Heavy Armor Special Attribute:

Level 1: Stops 10 points, equal to an APC
Level 2: 20 points, light tank
Level 3: 30 points, WWII medium tank
Level 4: 40 points, 1960's MBT
Level 5: 50 points, modern MBT, battleship
Level 6: 60 points, advanced mecha

(Note: The Force Field Special Attribute has the following gradation: 15, 30, 45, 60, 75, 90.)

Doing a little research among various Hero resources (such as Golden Age of Champions and Danger International) gives us the following results (Note: the DEF numbers have been averaged together to produce a workable result.):

10 = M113 APC: 8 DEF
15 = 10 DEF
20 = M-2/M-3 Bradley APC: 11 DEF
30 = M4A1 Sherman Tank: 13 DEF
40 = M60-A3 MBT: 16 DEF
45 = 18 DEF
50 = M-1 Abrams MBT: 20-21 DEF
60 = 26 DEF
75 = 32-34 DEF
90 = 40 DEF

Note that in BESM the armor stops X number of points of damage, much like a HERO Force Field or Armor. But BESM doesn't use STUN, so the DEF results here really only apply to BODY damage. For Armor, one should use the results as given (i.e. a character/mecha with Heavy Armor 6 has 26 DEF Armor). For Force Field, one might want to multiply the DEF x 1.5 to get a result. Note that this would give someone with a Level 6 BESM Force Field a 60/60 DEF Force Field in HERO terms! However, Ryoko in BESM can do a max of 60 points of damage with her energy sword, so she couldn't touch the character with that 90 point Force Field anyway. Thus, the numbers may work. As always, your results may vary.

These DEF numbers allow us to double check the damage values for attacks. As stated, Ryoko can do 60 points of damage with her beam sword. In BESM she can damage a Abrams M-1 MBT (for 10 points) as it has 50 points of Heavy Armor. Thus, in HERO System her attack has to be able to do at least 21 BODY, as the M-1 has about 20 DEF. 6 dice of Killing does 21 BODY on average. A 5d6 Killing Attack will do 17 BODY on average, more if Ryoko gets lucky. This comes out just about right.


These are "normal" skills and talents that don't require high-technology, magic, or esper/psi powers to explain. When converting read over both the character write-up and the power in the BESM rulebook in order to get an idea for the exact method to convert the Attribute. The following are only suggested translations for the Attributes.

Animal Friendship		Skill:  Animal Handler, PRE "Only vs Animals"
Art of Distraction		Skill:  Oratory, Persuasion, Seduction, extra PRE
Aura of Command			Skill:  Oratory, extra PRE
Combat Mastery			Combat Skill Levels
Divine Relationship		NA (Allows PC to reroll dice via "divine favor," GMs may want to allow HERO 
				PCs to buy Luck in order to simulate this. Recommnded value of 1d6 Luck per 
				level. Max of 6d6 of Luck.)
Flunkies			Followers (not combat capable)
Focused Damage			Talent:  Find Weakness, or extra damage or Armor Piercing (Note:  Focused 
				Damage only affects a single attack.)
Gun Bunny	
	Dead Eye		Combat Skill Locations vs Hit Locations and/or Range Modifiers
	Lightning Draw		Fast Draw
	One Bullet Left		Allows PC one last shot after they have run out of ammo. A suggestion would be
				dice of RKA equal to the PC's pistol with a single recoverable charge, and a 
				Trigger:  "Runs Out of Ammo." The charge is recovered and the Trigger reset by 
				sliding in a new clip.
	Portable Armory		Variable Power Pool of guns
	Steady Hand		Combat Skill Levels to counteraction modifiers due to being in motion.
	Two Guns		Skill:  Two Gun Fighting
	Weapons Encyclopedia	Skill:  KS:  Firearms on a 16- to 18-
Heightened Awareness		Danger Sense
Highly Skilled			NA (Allows more skill points)
Kensei (Japanese:  "Sword Saint")
	Blind Fighting		Combat Sense
	Chambara Master		Levels with Move By, or all Martial Arts maneuvers with the FMove element.
	Judge Opponent		Skill:  Analyze Style (Note, this skill works without seeing your opponent 
				fight, and is based on such elements as posture, GMs might want to allow a form
				of Detect)
	Katana Space		Allows PC to keep his sword hidden somewhere on his person. Concealment on an 
				18- (or greater) "Melee Weapon Only" is one suggestion, as is reducing the Foci
	Lighting Draw		Fast Draw
	Precise Stroke		Combat Skill Levels vs Hit Location modifiers.
	Two Weapons		Skill:  WF:  Off Hand, Two "Gun" Fighting
Massive Damage			NA (Increases damage with all attacks.)
Mechanical Genius		Skill:  Electronics, Mechanics, Inventing. Also, possible Transform vs Gadgets 
				(broken to repaired).
Organizational Ties		Perk:  Rank, Perk:  Contacts, Well Connected
Personal Gear			Possible Variable Power Pool of Gadgets.


Special Attributes need to be examined on a case-by-case basis and translated depending on the specifics of the character and the Attribute in question. Most of the Special Attributes are fairly self-explanatory, but the exact mechanics depend on the character with the Attribute.

Astral Projection		Desolidification, Leaves Body Behind. Note that this power is really several linked 
				powers in one (it includes Flight and Life Support) and the exact speed a character 
				can move while Astral varies on the level of the power.
Contamination			Transform
Dimensional Portal		Extradimensional Movement:  "Pocket" Dimension
Dynamic Sorcery			Variable Power Pool
Elasticity			Stretching, also Combat Skill Levels in hand-to-Hand
Electronic Counter-Measures	The exact nature of this power depends on the translator's wishes. Suggestions 
				include Change Environment, Flash, and Images.
Environmental Control		Change Environment
Exorcism			The exact nature of this power depends on the translator's wishes. Suggestions 
				include Extradimensional Movement, Drains, Dispel, and do on.
Extra Arms			Extra Limbs
Features or Accessories		Depends on specific Feature or Accessory
Flight				Level 1:  120" per Turn
				Level 2:  360" per Turn
				Level 3:  1050" per Turn
				Level 4:  2100" per Turn
				Level 5:  4000" per Turn
				Level 6:  8000" per Turn
				See BESM entry for specifics.
Force Field			See Damage and Defenses above. Note:  Force Fields may have various advantages 
				attached - see BESM entry for specifics.
Ground Speed			Level 1:  80" per Turn
				Level 2:  160" per Turn
				Level 3:  360" per Turn
				Level 4:  480" per Turn
				Level 5:  1050" per Turn
				Level 6:  2100" per Turn
				See BESM entry for specifics.
Healing				Healing Aid. Can restore lost limbs. Note: all Healing is at a "per minute" basis
Heavy Armor			See Damage and Defenses above
Heightened Senses		Various Enhanced Senses
Illusion			Images
Insubstantial			Desolidification. See BESM entry for specifics. Note:  at high levels this power 
				comes with "Variable Special Effects."
Invisibility			Invisibility. See BESM entry for specifics.
Item of Power			Special Focus
Jumping				Superleap
Life Support			Life Support. See BESM entry for specifics.
Light Armor			Level 1:  2-3 DEF
				Level 2:  5-6 DEF
				Level 3:  7 DEF
				Level 4:  8 DEF
				Level 5:  9 DEF
				Level 6:  10 DEF
Magic (Psionics)		See BESM entry for specifics. This usually means the character has a framework of 
				some sort.
Meld				See BESM entry for specifics. Personally, I'm not 100% clear on how to define this 
Metamorphosis			Either:  Shapeshift, Multiform, or Transform (other).
Mind Control			Mind Control
Mind Shield			Mental Defense. A character with Mind Shield adds the bonus for the shield to their 
				MIND or SOUL (which ever is higher) and then does the following:  
				[Result x 2.5]/5 + 5 to determine total Mental Defense.
Natural Weapons			Hand Attack or Hand Killing Attack
Own a Big Mecha			See BESM entry for specifics.
Place of Power			Character has a location that gives them an END Reserve that they can use instead of 
				their own END (i.e. END UBO). This is an immobile area.
Precognition			Clairsentience, Precognitive
Regeneration			Regeneration
Reincarnation			Possible if Fuzion/Hero Creator/Creation Workshop/5th Edition Regeneration rules 
				are used.
Sensors				Telescopic Enhanced Senses. See BESM entry for specifics.
Servant				Followers (Combat Capable)
Shape Change			Shapeshift and Disguise. See BESM entry for specifics.
Shield				Focused Heavy Armor. See BESM entry for specifics.
Sixth Sense			Detect:  (Various)
Size Change			Growth/Shrinking. See BESM entry for specifics.
				Level 1:  1 Level Growth/0 Levels Shrinking
				Level 2:  2 Levels Growth/1 Level Shrinking
				Level 3:  3 Levels Growth/2 Levels Shrinking
				Level 4:  6 Levels Growth/3 Levels Shrinking
				Level 5:  27 Levels Growth/7 Levels Shrinking
				Level 6:  32 Levels Growth/10 Levels Shrinking
Space Flight			Flight useable in Space. See BESM entry for specifics and range of speeds.
Special Defense			See BESM entry for specifics. May include Life Support.
Special Movement		See BESM entry for specifics. This type of movement is usually an altered form of 
Speed				See Movement Above. Note that at Level 5+ this Attribute may make one faster 
				than someone with the Ground Movement Attribute.
Spirit Ward			Energy Blast or Ranged Killing Attack Only vs Supernatural. Also Force Wall vs 
Star Flight	FTL.		 See BESM entry for specifics.
Stealth				Increased Stealth Skill. 
Super Strength			See Characteristics Above
Swarm				See BESM entry for specifics. Probably a form of Desolid/Flight or Multiform.
Telekinesis			Telekinesis
				Level 1:  -23 STR
				Level 2:  -8 STR
				Level 3:  10 STR
				Level 4:  28 STR
				Level 5:  48 STR
				Level 6:  60 STR
Telepathy			Telepathy. See BESM entry for specifics.
Teleport			Teleport
Transmutation			Transform
Tunneling			Level 1:  ~1" per Minute
				Level 2:  ~1" per Turn
				Level 3:  2" per Turn
				Level 4:  16" per Turn
				Level 5:  48" per Turn
				Level 6:  160" per Turn
				See BESM entry for specifics.
Water Speed			Level 1:  24" per Turn
				Level 2:  48" per Turn
				Level 3:  96" per Turn
				Level 4:  200" per Turn
				Level 5:  400" per Turn
				Level 6:  800" per Turn
				See BESM entry for specifics.
Weapon Attack			Allows for a "special attack." See Damage and Defenses above and the BESM entry 
				for specifics.


These are fairly normal, everyday skills. Interestingly enough, in BESM the cost of these skills varies on the genre. For example, in a martial arts campaign, and and all combat skills are expensive, while in a teenage romance game it's cooking and sports (among others). Note that a BESM skill is often several HERO skills and that BESM skills can be specialized into a specific aspect of a certain skill. The suggested HERO skills are just that, suggestions. Note that having just a single level in a skill is about equal to a HERO 11-.

Acrobatics		Acrobatics and/or Breakfall
Animal Training		Animal Handler
Architecture		KS/PS Architecture, Construction, etc.
Artisan			PS:  Specific Skill
Biological Sciences	SC:  Specific Skill
Boating			TF:  Small Water Craft
Burglary		Lockpicking and/or Security Systems
Business Management	PS:  Business Management, also SC:  Accounting, etc.
Computers		Computer Programming
Controlled Breathing	Talent:  Simulate Death
Cooking			PS:  Cooking
Cultural Arts		KS:  Specific Skill
Demolitions		Demolitions
Disguise		Disguise
Driving			TF:  Ground Vehicles, Combat Driving
Electronics		Electronics
Forgery			Forgery
Gaming			KS:  Specific Skill
Interrogation		Interrogation and/or Talent:  Resistance
Intimidation		PRE bonus
Law			KS/PS:  Specific Skill
Linguistics		Extra Languages
Mechanics		Mechanics
Medical			Paramedics, KS/PS:  Specific Skill
Military Sciences	Tactics, and/or KS/SC:  Specific Skill
Navigation		Navigation
Performing Arts		Acting, Oratory and/or KS/PS:  Specific Skill
Physical Sciences	SC:  Specific Skill
Piloting		TF:  Air Vehicles, Combat Pilot
Poisons			SC:  Toxins
Police Sciences		Criminology, Forensics
Riding			TF:  Horses, Riding
Seduction		Seduction
Sleight of Hand		Sleight of Hand
Social Sciences		SC:  Specific Skill
Sports			PS:  Specific Skill
Stealth			Stealth
Swimming		Swimming and/or PS:  Specific Skill, or TF:  SCUBA (etc.)
Urban Tracking		Shadowing
Visual Arts		PS:  Specific Skill
Wilderness Survival	Survival
Wilderness Tracking	Tracking
Writing			PS:  Specific Skill

Archery			WF:  Bow
Gun Combat		WF:  Small Arms
Heavy Weapons		WF:  Varies
Melee Attack		WF:  Common Melee Weapons, Common Martial Arts Melee Weapons
Melee Defense		Combat Skill Levels:  DCV Only, Only with Weapon
Ranged Defense		Combat Skill Levels:  DCV Only, Ranged Attacks Only
Thrown Weapons		WF:  Assorted Thrown Weapons
Unarmed Attack		Combat Skill Levels:  OCV HTH Only
Unarmed Defense		Combat Skill Levels:  DCV HTH Only


This are normal, everyday problems and disadvantages. As will all other Attributes and Skills, the following is only a suggestion, and examination of both the character in question and the rulebook is a must.

Ageism			Distinctive Feature and/or Physical Limitation
Attack Restriction	Psychological Limitation
Awkward			Physical Limitation and/or DEX minus
Easily Distracted	Psychological Limitation
Girl/Guy Magnet		Physical Limitation
Inept			Physical Limitation, Reduced Combat Value
Marked			Distinctive Feature
Nemesis			Hunted and/or Rivalry
Not so Fast		Reduced Running
Not so Strong		Reduced STR
Not so Tough		Reduced BODY
One/No Arms		Physical Limitation
Owned by a Megacorp	Physical Limitation
Phobia			Psychological Limitation
Physically Unappealing	Distinctive Feature, Reduced COM
Recurring Nightmares	Physical Limitation
Red Tape		Watched
Sensory Impairment	Physical Limitation
Significant Other	DNPC
Skeleton in Closet	Secret ID
Wanted			Hunted


These are more unusual Defects, and more associated with paranormal characters (or vehicles).

Awkward Size			Growth and Distinctive Features
Bane				Susceptibility
Cannot Talk			Physical Limitation
Cursed				See character's write-up
Diminutive			Shrinking and Distinctive Features
Hanger Queen			Physical Limitation
Involuntary Physical Change	Accidental Change
Magical Restrictions		Physical and/or Psychological Limitations
One-Way Transform		Accidental Change and/or Multiform
Restricted Ground Movement	Restricted Running
Restricted Path			Physical Limitation
Vulnerability			Vulnerability

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