I may have mentioned that I'm quite enamored with the OneDice system from Cakebread & Walton, having now purchased their books for Urban Fantasy, Steampunk, Cyperpunk, and Fantasy. I think I've noted a bug in the system what needs house-ruling. The bug is so far specific to Fantasy.
Alright, so in OneDice you roll 1d6+Stat+Skill, aiming for a target number. Nothing new. In combat, that target number is the opponent's Defense. (Spelled Defence in the book, because British people) Defense, for PCs, is determined by taking the better of a character's Strong or Quick and multiplying it by three.
This formula gives most demihumans Defense of 9, because elves and halflings and such have Quick 3 and Orcs have Strong 3. Trolls, all of whom start with Strength 4, have 12 Defense. These are raw numbers without any armor or shields.
Why is this a problem? Well, I'm glad you asked. With the exception of Trollish Strong, no PC can start with a stat higher than 3. Similarly, no character can start with a skill higher than 2.
Let's make an Orc warrior. I have Strong 3 just because I'm an Orc. I also max my Blades skill at 2. In combat, I roll 1d6+3+2. I cannot hit a PC Troll in combat. The highest I can roll is 11, and all PC Trolls have Defense 12 without armor.
Hell, even against other types of humanoids, my maxed-out Orc only has a 1/3 chance of hitting. All Elves, Goblins, and Halflings have Quick 3, giving them 9 Defense. Adding my Strong 3 and Blades 2, I still have to roll a 5 or 6 to beat their Defense score. If they put on any armor, I'm sunk.
In addition, the formula for determining a PC's defense does not apply to monsters. Monsters, even NPCs belonging to a playable race, appear to have utterly arbitrary Defense scores, similar to the AC scores of monsters in older versions of D&D.
Defense= Quick + Skill+3. In hand-to-hand, this is going to be the character's appropriate weapon skill. (Blades, Bruiser, etc.) In ranged combat, this will be Acrobatics. Armor adds to Defense as per the table. This applies to monsters as well, since their weapon skills are usually noted. Particularly large, armored, or otherwise tough opponents can get a bonus equal to a type of armor. (A monster with thick fur might count as slightly armored, a lizard man might count as wearing medium/mail, etc.)
Take a look at another Troll PC. Trolls begin with Quickness of only 1 or 2, plus probably 2 points in a weapon skill. If my maxed out Orc gets into a scrap with this Troll, he finds himself up against a Defense score of 7 (2+2+3). He now needs a 3+ on a d6 to hit the Troll, whereas before it was literally impossible to hit the Troll. This Orc can now hit an unarmored Elf (Defense 8) on the roll of 4+. Keep in mind this Orc is a character designed to throw down.
One thing I should've noted earlier: Every OneDice character gets 6 Stunt Points per session, and those points can be used to ignore an enemy's Defense, but I don't think that remedies the situation when you find starting characters being literally unable to hit opponents with Defense 9 or 12, as Stunt Points are a finite resource and the Defense bypass is only for one attack.
I haven't checked the other OneDice games, but I suspect there will be a similar issue since I think the system is essentially the same. I'll check Urban Fantasy next, since it's the one I most want to actually run.
If I've somehow done the math wrong on my initial examples demonstrating the math problems in this system, please someone tell me. I'd love to be wrong about this, but I think the game is pretty straightforward.