What Makes a D10 System a D10 System?

[Ninjadeadbeard]

Pretty much what it says on the can. I have been noticing I enjoy games that use d10's as their resolution die for a while now. Ever since I played Artesia (Fuzon) with some friends, I fell in love with the brutal and lethal nature of combat, and I wanted to recapture that feeling with my party as I return to DMing.

Trouble is, 3.X and most similar systems seem to lack the lethal edge I fell in love with, and Artesia itself (while a refined Fuzon system) is utterly beholden to its own setting, in addition to a wildly out of control magic system that hurts my head.

So, while I would like to somehow convert 3.X into a D10 System, I think that may be more difficult (and largely unnecessary) than what I bargained for. tl;dr: What are the key characteristics of a D10 System, and how can I translate the concepts of D&D to such a system?

[Eldan]

Wouldn't that just be that system specifically, rather than d10 systems in general? Because I see no reason why any systen with a d10 (say, everything by White Wolf) should be deadlier.

[Kalmageddon]

I don't see anything that would be needed to make a d10 system outside of, you know, using a d10.
Maybe less random variables compared to multiple d6 system or a typical d20 system?

Outside of that I can't see anything in particular that makes or breaks a d10 system.

[Fouredged Sword]

Well, if you want a lethal d10 system shaped from 3.5 I would do the following.

1) Start with E6. Keep the player level low so threats remain threats rather than being leveled past and left in the dust.
2) Cut all base level effects in half. Defense is 5+dex mod rather than 10+dex mod. Armors and natural armors are cut in half. Base attack bonus is cut in half, round down. Over 6 levels bab is ether +3/+0(full), +2(3/4ths) or +1(half). Personally, I would leave stat bonuses alone. It will make them more important. Saves are divided in two, as well as base DC's (remember, you can leave the stat bonuses as is), I would round UP with saves, giving you +3+stat for a good save and +1+stat for a bad base save. Spell DC's can be 5+spell level+relevant stat.
3) Use the vitality point system for replacing HP. Remove the Con bonus to vitality points. You get your Con score in HP and 6DX dice of vitality points (though I would use 1/2+1 auto rolls rather than rolling dice). The lack of resurrection magic will make those DC15 fort save to survive very nerve wracking, and crits will drive your party up the walls with fear. Crits will be much more common on a D10, so the tension will be high.

[Airk]

Yeah; The question you asked and the question you want an answer to are unrelated.

A "d10 system" is any system that uses d10s. Of which probably the most well known is Storyteller, but it also includes Unisystem and a bunch of other stuff. There is ZERO correlation between "uses d10s" and "lethality." There are no other "key characteristics" of such a system.

Honestly, I wouldn't waste your time trying to convert 3.X to D10s, because what would the point be? If you want to make the game more lethal, look into what prevents it from being lethal in your mind and address those problems.

[Millennium]

I hadn't been familiar with the Fuzion system before this, but if I'm reading this right, then in the way you played it (d10 resolution) the core mechanics aren't so different from d20. It just uses a different die: you're still rolling a flat chance of success, rather than using dice pools or a bell curve.

Given this, I'd propose that Fuzion's deadliness, relative to d20, doesn't come from the die it uses. More likely, I think, is that it comes from the way that the two systems handle injury. Basically, stock d20 makes it easy to get tougher, while Fuzion makes it hard.

The thing about most d20 systems isn't really just that it's easy to get tougher: it's also automatic. Unless you're doing something funky with monster classes, you're all but guaranteed to get at least a few hit points every time you level. Furthermore, you gain XP (and thus progress toward leveling) more or less automatically as the game goes by: it happens as you defeat monsters and overcome obstacles.

Fuzion is different. You don't get Hits automatically. In fact, you can't even touch them directly: to get more Hits, you have to raise your Body stat, and this is a nontrivial task. It's costly in any event, but it only gets more so as you grow up, and eventually (and at relatively low numbers) it just gets prohibitive.

As an extremely simplified way of capturing this in d20, I'd recommend something like the following: Ordinarily, characters have a maximum number of Hit Points equal to their Constitution score.
Characters without a Constitution score have a maximum number of Hit Points equal to their Charisma score instead.
HP does not improve as characters level. "Hit Dice" should still be tracked, in order to handle effects which depend on them, but are otherwise just numbers.
Toughness still works normally, as do other effects which directly affect your maximum Hit Points.
Damage values are unchanged.

In this setup, as you get stronger, you become more able to reliably drop enemies quickly, but if someone gets the drop on you, you're still in big trouble. Toughness and DR remain valuable for those times when things slip past your awareness, but AC, evasion, and not allowing yourself to be surprised work better. Cover is best of all.

Does that sound like it might make a good start?

[Ravens_cry]

A d10 system uses a d10 as its primary die.
How it uses it determines its characteristics though.
A system that uses several d10 as a dice pool is going to have different kinaesthetics and game feel than a system that uses 2d10 percentile system, and that will be different again from one that uses 2d10 totalled together, and different again from one that uses 1d10 rolled alone, and so on.
There's other qualifiers as well. Is it meet and beat for DC or just meet, is it roll over or under, do you roll to defend or just to attack or vice versa, or both even.
Does it use one unified mechanic for most or all operations, or is there a bunch of subsystems that all feel quite different. What, if any, other dies does it use?
What's the 'turn' duration interval?
Is it a set thing, or can it change depending on situation? How granular is it. Does it strive for simulation and granularity, does it go for a certain genre or narrative feel and tone, or does it simplify mechanics to ease gameplay?
How does it handle injuries? Can characters come back from the dead, and if so, how hard is it to pull off?
Are the mechanics symmetrical (NPC use the same rules as PC) or do players and non-player characters basically operate in a different universe. If, as is likely, somewhere in the middle, to what extent? How much authority goes the game master have? How obscured and occluded are the rules?
All these questions and more are much more informative of the system than its primary die, though that can tell you something, just not a lot on its own.