My love of all things D100 in TTRPG’s is a real thing. If I could only have one (system type or even game), it would and almost is D100 games.
There are games for any period, theme and play style, or to be more precise, any play style can be accomodated, but it needs some help with Pulpy style.
The most commonly cited complaints with D100 games are;
The d100 roll under die rolls are swingy and harsh. Why did I pass on a 64, but fail on a 65? This often speaks more to the literal nature of some gamers, not the game itself.
The system tends to be lethal and unforgiving, which only suits some styles of play and themes. This is often coincidental, the combat effects reflecting more choice only, not necessarily the severity of the effect.
The games feel old. The core systems have not changed in 40+ years and some of the mechanics seem dated. There is often seems to be a lack of “slickness” to their presentation compared to a lot of newer (or older) systems. A system that does not need fixing every new edition? Heresy!
Ok, lets look at these three complaints.
The d100 roll under system has a wide range, but a sharp win/loose threshold. This is true as written, but mostly an illusion in comparison to other games. In any other game where dice are used, the same thing happens, just not in as much detail.
The granularity of d100 games and the non curve spread seem to exaggerate perceptions of an abrupt shift and I think the roll-under dynamic adds a subconscious negative vibe to the system, but is it really any different to a d20 roll high game? If a 17 hits, but a 16 misses, we seem to accept that, but not the example above.
Conversions are easy to and often there is a D100 game that cleaves close to the intended convert. Historical Witcher anyone?
Even games with a curve still have a pass/fail threshold, it just looks softer.
“Curved” games tend to reward small modifiers more easily, sometimes illogically, where linear games have a more granular growth.
One solution is to use the larger range either overtly or on a case by case basis to indicate the severity of a fail or the success of a pass. For example, if a roll falls within 10% of the pass mark either way, this can indicate a “soft” pass/fail like a recoverable fumble or a pass with complications. This is actually a benefit of the larger range available.
Apart from a simple fix like luck points which may allow re-rolls or die inversion, the system itself actually can provide the solution and quite elegantly. If you use a slightly different die mechanic to the accepted fixed 2d10 with a +/- skill chance mods for difficulty, you can even add a curve.
Regardless what system you use, a D100 generic mechanic can be applied.
A risky or challenging test roll of 2d10 and take them as rolled-i.e. pre allocated*, an standard test allows taking them the best way or you take them the worst way for a perilous test (then adding more dice to the pool etc).
This system adds a curve, requires no math and has no “dead end” caps. There is now a built in, roughly 75% chance of hitting a number under 50 for a standard test, not the linear 50%. This also promotes the idea of a decent skill base, but slow growth.
It is recommended that no skill should ever be over 99% with this system, although there are plenty of ways of fixing this if needed like the value over being added to a passing contested roll but “00” (being effectively nothing) always fails.
By adding more die to the equation, there is no need to even add or subtract from the base skill roll. Three die, using a take the best/worst combination of two also adds the chance of more critical chances (see below)*.
Another way of handling any difficult test in any die based RPG is to simply break the test into parts or layered success rather than just a simple yes/no test. This adds tension and forces greater difficulty simply by adding layers of story elements.
The “doubles = critical effects” (passing or failing) smooths out the dated and clumsy mechanics like the mathy lower or higher 5% of skill pass/fail, crit chances and slots in seamlessly with the mechanic above. I have always struggled with equal crit or fumble chances shared by characters of vastly different skill levels.
This fixes much of the mechanical clumsiness of point three and even a little of point 2. One consideration is to limit character control of skill point allocation (maybe to 10 units per growth allocation) so doubles don’t dominate (or not).
Like the base roll, the actual critical rolled may also vary in effect.
Extreme end critical pass/fail results would be pretty straight forward, very clean results “11” would be a guaranteed, yet unexciting success, “00” is a potentially embarassing fumble, while crits closer to the actual test threshold, and the higher the better, would be more pronounced.
A very highly skilled character for example, able to get a passing “88” would be able to pull off a miraculous success. This has the effect of making critical pass rolls closer to the actual skill level, the ideal result. This adds to the brinkmanship feel of the roll under system. It also allows the GM to limit “mooks” to values under potentially brutal crit levels. A simple little table of critical pass/fail results can be employed as a GM prompt.
Rather than a simplistic pass/fail roll, the dice become story tellers in their own right.
Point 2 is interesting. There is nothing actually stopping the d100 games from becoming as abstract and soft as d20 or other systems can be. This in fact is a way of making d100 games more “pulpy”, by increasing hit points and decreasing specific effects. The likelihood of player character death is a game specific thing.
Want simulated reality, genuine character fear and a feeling that any threat is real, then most d100 games offer that, but not because the d100 mechanic forces it. It is more because the d100 family of games have often postulated realistic character fragility is a valid option as part of their original anti TOG ethos. This “fresh eyes” look at what a TTRPG is, started to ask important questions early on.
The only way to get better, safer or more lethal in most d100 games is to be more skilled through training or experience. This is a mirror to life, much more realsitc than arbitrary levels, abstract hit points and AC bonuses. This by default elimnates the need for power creep inside the mechanics.
In a d100 game, stats are generally fixed, skills often capped and weapons and armour locked in, so all things being equal, only the better skilled character has the advantage. A ceiling is set and it is realistically low, part of the secret of the systems longevity.
The d20 based 13th Age does exactly the opposite, tying all aspects of the character from damage dealt, AC, hit points etc directly to character level. This is a favourite because if you are going to pay into the theatrical abstraction of a d20 game, it does it both feet in.
“Softer” games like The Original Game (only just older than the first d100 game that directly sprang from dissatisfaction with TOG), have always used abstraction and generalised mechanics based on the orignal wargame it was based on (Chainmail). This means characters feel less in peril. They can pay more into the game without fearing the consequences of their actions to the same degree as a d100 game.
there is nothing to say TOG could not feel more perilous, but it simply does not.
Levels, generic hit points (with no other effects), fast and easily accessed healing, even resurrection are just some of the gameish mechanics d20 games use to get their job done and if it suits, then fine. D100 games can actually use these as well, just choose not to.
I will ask the reader, if a sword does massive damage to an arm, should that just be rolled into a pool of generic hit points until they are reduced to below zero, or should it actually effect the character’s ability to use skills and gear reliant on that arm? Your call, but to me one is realistic, the other is closer to a simple video game. Even d100 games that do use hit point pools, usually have critical tables that align damage to physical effects.
I feel strongly that TOG is simply a natural evolution of a wargame and it shows, where d100 games were a genuine revolution into a true TTRPG thinking. It would have been interesting to see, if d100 games came first, whether a clunky d20 system would have even been concieved.
A fix for that in some of our few d20 E6 games was to actually damage characteristics on critical hits, an idea borrowed from the Traveller RPG. This acted as a reality check that suited the low powered E6 variant of 3e/Pathfinder. Characters suddenly got into a more d100 mentality, one even saying it felt more like CoC than d20. It really bought out to me the dissociation with reality that an abstract hit point pool creates.
This brings us to the last point.
The games associated with d100 are often older games such as Runequest (the original d100 game recently re-released), Call of Cthulhu, celebrating it’s 40th anniversary and the generic BRP family.
The reason for this is, unlike d20 games, the d100 mechanics worked from day one with only minor evolution needed. The latest versions of d100 games and there are many, all trace their mechanical heritage and functionality (not just terminology) back to the first.
It is basically true to say if you know one, you have a solid grounding for the rest. The systems are so logical and straight forward, bullet proof even, you could wonder why any other systems are needed other than to populate a healthy hobby landscape. D100 games are evolving, but nothing dramatic and it all has a take it or leave it feel****.
It is true also that most available d100 materiel is cross compatible to some degree, even if 30 years separates them. A CoC monster from 1st edition is not a big stretch for a 7th ed game and conversions are straight forward (some have stayed basically unchanged).
This is also why there is no OSR or retro-clone movement in the d100 community, because there is no habit of drawing lines in the sand and making gamers commit to specific editions, which are largely incompatible.
Ironically, the only major change mechanically is a move in 7e CoC away from the original TOG, 3d6 characteristic generation model into true percentiles, but even that is an official shift to an already used d100 mechanic (CHR x5 = #%). Hardly enough to create a retro sub-culture as conversions are pretty simple either way and the chrs are still generated the same with 3d6 anyway.
There are plenty of incompatible d100 games sitting outside the BRP family, such as Rolemaster, Bare Bones, D100 Dungeon, but even then, the base mechanics are similar and the core concepts are in the same ball-park.
*I use red and blue die. If the player is handed one of each, the test is standard (read the red as tens and then the blue as singles). If the test is easy, they player is presented with two blues, or two or more reds if hard. The look on their faces when they go to unlock an innocent looking box and you hand them four reds for a nearly impossible reflexes check is priceless (until they pull it off!). The GM can also let the players roll based on their assumptions, but disguise the values (read them differently after the roll, maybe even withholding the real result or why it went wrong).
**The original RPG has shifted from a, sometimes negatives and sometimes positive values are good to a positives only dynamic. From high/low/middle “crunch” and vastly different sub systems over just 5 editions. With few exceptions none of these are cross compatible. This does not even cover all the spin-offs that often depart heavily from the originals. Most of the changes are there to address the inherent issues with the system. No levels, no unrealist and hard to fathom abstractions, no untouchable characters immune to arrows shot by lesser beings, no shruggling off a dozen axe blows, no odd game only based abstractions. D100 games have only a reality cap hampering them, meaning all sword thrusts can kill, any Dragon is always dangerous and actions always have consequences.
***I recently dug up my copy of the Black Company companion for 3e TOG. This is a very good example of a system in crisis. Some of the characters are level 50+, have half a thousand hit points, can attack five or six times with guaranteed sucsess (but do relatively little damage) and do not in any way align with my take on the books. To be honest, most of my favourite fiction (the Malazon books, Urth of the New Sun, The Black Company chronicles, John Carter of Mars, The Dark Tower, Tolkein etc all have relatively fragile heroes, no one is immune to harm from any level of foe, in fact it is hard to find any fiction that models TOG tropes except super hero comics. One of the greatest ironies is the Mythras release of their Lyonesse book which handles the Vance books that inspired the original “Vancian” magic system used in TOG better than TOG!
****One of my few dissapointlments in D100 games is the new Warhammer RPG. For all its gloss, wonderful art and production values, it is a simple game over complicated, with bit glaringly missing (shields!). If this was a different system, I would be gutted, especially as I committed to the massive an d amssively expensive “Enemy Within” campaign, but the reality is, being a d100 game, I have many easily accessed tools to fix any problems. I could even play the whole campaign using another d100 system with little difficulty, even 1st ed Warhammer.