The Case for Level Zero

What evidence is there in classic version of D&D for the status level-0 characters? This could be important for a few reasons: (1) It would make a difference in the statistics for mass-combat armies, whether the basic troop type was level-0 or level-1 or something else; and (2) It could provide justification for common 1st-level boosts (as in ability scores or hit points), under the statistical survivability analysis that we've done via the Arena simulation program (link).

Original D&D

In Original D&D, 1st-level characters are distinguished from Normal Men in at least three ways.

1. Starting-level fighters are given the level title "Veteran", implying that some significant action had to take place prior to reaching the 0-XP level (Vol-1, p. 16).
2. Veterans are given Hit Dice of "1+1" (that is: 1d6+1; Vol-1, p. 17), whereas normal men such as Bandits, et. al., are given "Hit Dice: 1 die/man" (that is: 1d6 with no addition; Vol-2, p. 6). 
3. Veterans are also given fighting capability in the Chainmail-based system of "Man + 1", while normal men would presumably be simply "Man" (with no bonus; Vol-1, p. 17). 

That said, in the d20-based "Alternative Combat System" combat and saving throw tables, there is no distinction in abilities; a footnote reads, "Normal men equal 1st level fighters" (Vol-1, p. 19). But other than that, we see that even in the earliest work there was a clear distinction drawn between 1st-level fighters and other Normal Men (even those who appear in large armed groups, making a living via combat and raiding, with high-level leadership, as per the Vol-2 listing for Men such as bandits, brigands, pirates, etc.).

D&D Sup-I: Greyhawk

Here's a puzzle: what hit dice do Normal Men have under D&D Supplement-I, Greyhawk, using the alternate hit dice rule (p. 10: e.g, d8's for fighter levels)? The text says, "Use of this system is highly recommended, but if it is used all monsters should be based on the 8-sided die system." Does this include Normal Men, or merely every other being in the monster listing? If the former, then they are here equal to 1st-level fighters and unique compared to any other ruleset (see below); but if the latter then they have just become less strong than Orcs, for example.

Personally, I think this switch to d8-dice for monster hits was one of the major, early missteps in the evolution of D&D. So much simpler to roll batches of d6's for this purpose, and I see no compelling need for expert fighter dice to match monster dice. 

Swords & Spells

Gygax's Swords & Spells supplement for mass warfare in Original D&D appears to have the first actual use of the phrase "0 level". The combat tables for average damage per figure, unlike the OD&D core books, have a separate row for level "0", with the footnote: "0 Level is normal man-type (i.e., 1 die or less, and not able to progress upwards in levels.)" (p. 25). The two-page spread of weapon-based combat tables in Appendix A are in fact entirely based on Level 0 combatants (p. 31-32), with modifiers for other levels applied from a prior page (p. 27).

These rules include different "Troop Classifications" in six tiers: Peasants, Levies, Regulars, Elite, Guards, and the combination Elite Guards. The latter are quite rare: "As a rule, guards should be limited to 10% of an army, and elite guards would surround the personage of the commander only, for example" (p. 5). But the following all-italic paragraph establishes that any 1st-level fighters qualify for this special category: "NOTE: Scale figures representing human/humanoid (and highly intelligent) creatures of 1st level or above or with 1+1 hit dice are always considered as having elite guard status. For example, the following types of troops are classified as elite guard status: Veterans (1st level fighters), Elves, Hobgoblins..." (p. 6). This status gives bonuses to formation, movement, morale, and melee. So in summary: 1st level is shown to be something very special indeed.

Advanced D&D

In Gygax's AD&D, there are even more copious distinctions made between 1st-level characters and those less than that. The Player's Handbook states, "It is important to keep in mind that most humans and demi-humans are '0 level'." (p. 106). The Dungeon Master's Guide notes in the section on hiring mercenary soldiers, "Note that regular soldiers are 0 level men-at-arms with 4-7 hit points each" (p. 30: again highlighting that even trained career combatants are 0-level by default; see also class followers on p. 16). The combat and saving throw tables here give a separate, reduced column for level 0 fighters (p. 74, 79). A footnote reads, "Dwarves, elves and gnomes are never lower than 1st  level (unlike halflings and humans, which may be of 0 level)" (p. 74: possibly correcting PHB p. 106 above). A table on the campaign's "Typical Inhabitants" specifies combat ability of "0 level", or even as low as -1 to -3 from that mark for sedentary types, with hit points ranging from 1-3 to 2-7 (p. 88). Of peasant revolts it is noted, "Troops will be 0 level" (p. 94). For energy draining by undead, the stated rule is: "If this brings the character below 1st level of experience, then the individual is a 0 level person never capable of gaining experience again. If a 0 level individual is drained an energy level, he or she is dead (possibly to become an undead monster)" (p. 119). City and merchant guards are also 0 level (p. 191-192).

In the Monster Manual section on Men, the first thing stated is, "Normal men have from 1-6 hit points each." (p. 66), and this is reiterated in the following entries "Hit Dice: 1-6 hit points" for Bandits (Brigands), Buccaneers (Pirates), Dervishes (Nomads), Merchants, and Pilgrims. So in this regard the hit points are identical to those for Men in OD&D Vol-2 (actually downgraded for Dervishes), and it argues that the likely intent in OD&D Sup-I was also to maintain them at the level of 1d6 hits, less than 1st-level fighters or 1-hit-die monsters.

The DMG also has the following statement in the section on henchmen (p. 35):

Number of Prospective Henchmen: Human and half-orc characters suitable for level advancement are found at a ratio of 1 in 100. Other races have an incidence of 1 in 50. However, as most of these characters will be other than low level adventurers and already in a situation they are satisfied with  -  and humans more so than other races, unless the development of the area is primarily other than human - about 1 in 1,000 population will be interested in offers of employment as a henchman. NOTE: This figure must be adjusted by the DM according to the locale, for if  it  is an active adventuring area, the incidence of prospective henchmen might be as great as 1 in 200, while if it  is  a settled and staid area, incidence might be as low as 1 in 5,000.

Note the opening line, "Human and half-orc characters suitable for level advancement are found at a ratio of 1 in 100." If taken at face value, then this could have interesting demographic implications; however, it seems to broadly contradict the fact elsewhere that for about every 100 normal men, there is at least one leader of 8th-10th level, along with a host of other lower-level fighters (see Men: Bandits in the Monster Manual p. 66 and other places). And surely the claim that "Other races have an incidence of 1 in 50 [for level advancement]" is in even starker contrast with the footnote on DMG p. 74 that "Dwarves, elves and gnomes are never lower than 1st  level". So coming up with some synthesized interpretation for these different statements seems very challenging; they seem as though if coming from completely different campaign systems. And yet -- there is no doubt that level 0 men are the norm; the only question is what their relative frequency is (high or extremely high).

Unearthed Arcana

In the AD&D Unearthed Arcana work, Gygax implements a mechanic for gaining XP and advancing through 0-levels in two places: for the Cavalier and the Magic-User. For the former (p. 14):

A cavalier character must be of proper social class, and is usually of noble or aristocratic origin. Only those characters of Upper Class  social status may immediately enter into the cavalier class. Those of lower social standing are generally excluded from becoming cavaliers, but certain members of lower social classes may be so honored. Such a character must be sponsored by a higher authority  of  greater status, and begins first as a 0-level Horseman (a retainer for a Knight), then a 0-level Lancer, and finally becomes a 1st-level Armiger of the cavalier class. The 0-level Horseman starts at -1500  experience points and has 1d4 + 1 initial hit points. The Horseman becomes a Lancer at  -500 experience points and gains another d4 roll for cumulative hit points. The Lancer becomes a 1st-level cavalier at 0 experience points, and gains another d4 in hit points. In contrast, a character whose social standing qualifies him or her for immediate entrance into the cavalier class begins as a 1st-level Armiger with 1d10 + 3 hit points. The character’s hit-point bonus for high constitution (if applicable) is first received at either Horseman or Armiger level, and is then applied to each additional hit die from second level on as normal. The special abilities of the cavalier class are only gained when the character attains Armiger status.

These statistics appear likewise in the class table for cavaliers (p. 15). For the Magic-User, 0-levels are the mechanic by which one can use Cantrips even before the character can cast a 1st-level spell (p. 45):

Cantrips are the magic spells learned and used by apprentice magic-users and illusionists during their long, rigorous, and tedious training for the craft of magic-use. An aspiring magic-user or illusionist may use 1 cantrip per day as a 0-level neophyte (-2000 x.p. to -1001 x.p.), 2 cantrips per day as a 0-level initiate  (-1000  to -501), and 3 cantrips per day as a 0-level apprentice (-500 to -1). Cantrips must be memorized just as higher-level spells are.

So these below-zero-XP rules are broadly consistent in their application. In each case there are actually more than one 0-level in question (two for the cavalier; three for the magic-user). Somewhat oddly in my view, the increasing XP-per level is reversed for the 0-levels; the earliest levels actually require more XP, and the level closest to 0 the least (in both cases, just 500 XP to get to 1st level from the immediate predecessor).

(Side note: Post-Gygax, there was an AD&D-branded Greyhawk hardcover book with an appendix on running 0-level characters. However, those rules do not use standard XP, instead using a totally different AP point-buy system instead -- e.g., get an AP point and use it to boost an ability or buy a skill by one point -- and so we need not consider it further here.)

Holmes D&D

While the status of "0-level/normal men" is fairly consistent throughout all the Gygaxian works, the Basic D&D line veers off in another direction -- one which has caused a few mistakes and incorrect recollections on my part in the past. First, J. Eric Holmes started to dispose of them. Under "Non-Play Characters", he writes: "Generally, only the lowest level of character types can be hired, i.e. first level" (p. 8); that is, he seemed to collapse the distinction between 0-level hirelings and 1st-level henchmen in mainline D&D. Secondly, at the start of the monster list, he writes "Monsters' hit dice are 8-sided", and then three lines later in the lead-off Bandit entry, they get "Hit Dice: 1" (p. 22). So it's hard to read that in any way other than giving Bandits a full 1d8 hit points; a conceivable reading of Supplement-I Greyhawk (see above), but definitely at odds with the listing in the AD&D Monster Manual. On the other hand, the combat tables do include a row for "Normal Man" (p. 18) which didn't exist pre-Swords & Spells, but other than that I can't find reference or use of the term.

Edit: Zenopus Archives has pointed out on his site that in Holmes' original manuscript submitted to TSR, his combat and saving throw tables did not include any separate row for "Normal Man". Rather, they were inserted in an editorial pass by Gygax himself before publication of the final product. But apparently Gygax did not pick up on those more subtle areas where the concept was submerged (hirelings and hit dice). Thanks to Zenopus for that analysis (links: one, two).

Moldvay/Cook D&D

The Moldvay Basic and Cook Expert D&D rules take this a step further, by attempting to make almost every man in an adventure a member of some class. Now, Moldvay does state that, "A retainer may be of any level (0, 1, 2, 3, or higher) and of any class (normal man or a character class)" (p. B21), and he does include rows for "Normal Man" in the combat and save tables (p. B26-27). But that level is used mostly for minor non-human monsters (e.g., bats, rats, centipedes, insect swarms, goblins, kobolds, and mules). The Bandits which previously represented the canonical normal men are here declared to be "NPC thieves" who save as "Thief: 1" (p. B30); but while 1st-level thieves get 1d4 hit points, once again the monster entry simply says "Hit Dice: 1" -- which means 1d8 by the rules of the monster section -- so these seem out-of-joint. Also, a new monster type of "Noble" is given, and for these, "In the D&D BASIC rules, a noble will always be a 3rd level fighter. However, the DM may choose to make a noble any class and level... A noble will always be accompanied by a squire (a 2nd level fighter). A noble might also be accompanied by as many as 10 retainers or hirelings (usually 1st level fighters)" (p. B39-40).

Edit: Thanks to JB in the comments for noticing that I'd overlooked a dedicated monster entry for the unclassed "Normal Human" (p. B40); I missed this because it's the only place in this or any other ruleset where the descriptor is other than "Normal Man". The stat block gives them 1d4 hit points. The description says this: "Most humans are 'normal' humans, though people with certain professions (such as merchant, soldier, lord, scout, and so forth) help in some adventures"; my reading is that those "certain professions" are all classed by default (c.f., "Noble" above and all the soldiers in any B/X adventure). Finally, Moldvay gives a unique rule for advancement, far more generous than Gygax: "As soon as a human gets experience points through an adventure, that person must choose a character class."

In the Cook Expert rules, the only place the phrase "0 level" or "normal man" appears is in the matching combat/save tables, the rules for the legacy potions of heroism and control human, and the stats for seamen and the normal hawk. Mercenaries are not explicated one way or another (p. X22). However, in the catch-all monster entry for Men, they are all given a full 1 Hit Die and saves as "Fighter: 1"; including all of the types of Brigands, Buccaneers, Pirates, Dervishes, Merchants, and Nomads (p. X35) -- very much at variance with the OD&D and AD&D game lines. Likewise, all of the adventures in the X-series of modules specified base soldiers in any army as being universally at least 1st-level fighters: see modules X4, X5, the comprehensive army rosters for all of the Known World in module X10, and so forth.

Conclusions

While there is some attraction to the simplicity of the Cook/Moldvay method (all soldiers are at least 1st-level fighters), I do think that the core D&D system makes the most sense if we interpret things in the sense of OD&D/AD&D with a "0-level/normal man" class prior to 1st-level characters. This justifies 1st-level fighters having the title "Veteran", their improved attack/defense capability, the status that trainee wizards might have prior to casting their first spell, etc.

As usual, I frown upon special-case discontinuities such as that "0 Level is... not able to progress upwards in levels" (per Swords & Spells). In this sense, I look favorably upon Gygax's addition in Unearthed Arcana of some kind of rules for pre-1st-level experience progression. Even if we never expect to use that during gameplay for PC's, it gives us something to hang our hat on for the purpose of campaign-wide NPC demographics, and how the matriculation from 0-level to 1st-level might occur. (And even for active play, I've had at least one player in the last year take over an NPC lantern boy who started racking up a surprising number of kills and a developed persona -- moreso than his original dead PC -- and surely that should be rewarded.)

Here's what I think I would do for the unwashed masses in my "Original Edition Delta" games: Start at 0-level. Roll 3d6 in order for abilities. Roll 1d6 for hit points. Earn 1,000 XP to get to first level. On achieving 1st level, add 1 hp if becoming a fighter, or subtract 1 hp if a becoming wizard (minimum 1 hp before Constitution bonus). A slight wrinkle here is that 1st-level fighter graduates in this way could only have 2-7 hit points, but that actually matches the Original D&D Vol-1 text, and is on average the same as a 1d8 roll.

Note that I veer off from Gygax a bit here in the exact XP needed to graduate from 0-level. For both the cavalier and magic-user, he set the level immediately before 1st at 500 XP; although in both cases, there were other "negative" levels that one needed to progress through initially.  Looking at the standard geometric XP tables, with fighters starting at a 2,000 XP step for 1st level, the clear extrapolation is that the level before that should be 1,000 XP (i.e., half). In addition: under certain other demographic assumptions, having a 500 XP step may actually produce a greater number of 1st-level types than normal men, a result that we should certainly avoid.

A few notes for Book of War: statistically, these distinctions are all below the level of granularity recognized in that game. For example, say a target is wearing chain & shield (AC 4 in any edition above). If the attacker is 0-level, with d6 damage, against a d8 hit die, then the chance to score a kill with one hit is 11%; but if the attacker is 1st-level, with d8 damage, against a d6 hit die, then the chance is 21%. Any other permutation is somewhere within these bounds; but using the BOW d6-mechanic, all of these round off to the same 1-in-6 chance to score a kill (16.6...%). So that's why it's really nice that BOW is a statistically accurate representation of whichever edition of the game you normally play with, regardless of these small details; and at all times I can thus assume that common 1 HD human soldiers are, for simplicity, effectively the same as common 1 HD orcs (at least in reasonable lighting).

So we do like giving the 0-levels a chance to be heroes someday. But what implications does this have for campaign demographics or 1st-level abilities and hit points, having survived the 0-level to get there? More on that next time.