System Analysis is a sporadic series where we go over a specific game in a more indepth manner. The idea behind it is not only to see how the system works, but what that may mean for games you are running in it. Essentially, what it does well versus what it may do poorly, and what those mechanics mean for games being run in it. This week we are going over Dark Heresy by Fantasy Flight Games.
The Core Mechanic
Every system has a core mechanic, and contrary to some belief, the core mechanic is generally the core resolution mechanic. In other words, the core mechanic is what you do to determine success or failure, which in most systems involves a dice roll. In Dark Heresy the die of choice is the D100 or Percentile dice. All checks for a player's action is done by rolling 1D100 and comparing the result against the character's relevant stat - modified as appropriate for gear and skill level. If the percentile gets under the stat, the action is a success. If it goes over, the action is a failure.
This is then further complicated with degrees of success/failure. Degrees of success/failure are calculated by every 10 points above/below the target is considered a degree. So if you were rolling against a 55 and got a 36 you would have 1 degree of success (as you are 19 points below 55, thus just barely missing 2 degrees.) Degrees of success matter in the same way a critical success matters in other systems, and in ranged combat can determine how many times a gun hits someone.
Stats Determine Success/Fail
The next thing to know with Dark heresy is that with that core mechanic it means that the players' stats determine their chance to succeed or fail at any given task. Which means that, with starting stats averaging at aorund 30, that the game is set up for a lot of failure to happen in the beginning of the game. Now, with group rolls, this is less of an issue. If you have 5 players, odds are one person will make the awareness test. However, in single situations, it is very possible - and in fact even probable - that a character will fail about 70% of the actions they attempt to do. Keep this in mind, as it conveys a feel to the world that you may, or may not, like.
Rerolls and Adding Degrees
The last thing we need to touch on with this core mechanic is the Fate point system. Fate Points let players do a number of cool things. You can permanently lose a fate point to avoid death, which is the big use. However, you can also spend a fate point to re-roll a failed check or to add a degree of success to a roll. These last two are the big uses they see in game, and in important actions they let players turn around their failure into potential successes. However, fate points are limited. On average most players seem to get 2-3 at creation, and they can go very fast. However, they at least give a sense of hope that you can make the important things work out better. That is important to remember too.
What This Means
What all this means is that there is a lot of variance in Dark Heresy. A D100 is a big die, and it allows for a lot of randomness to come into play. This, combined with the limited ability for rerolls and low player stats can convey a sense that the player - or PC - is not in control. High level players begin to stack bonuses and stats to having ridiculously high success rates, but starting off you feel very small and very weak. This is by design, it seems, but is something that you as the GM need to be aware of going into the game. If your players don't do well with feeling weak, this may be a game to avoid. It can be frustrating having to constantly fail rolls because you only have 2 fate points, both of which are gone, and your best stat is only a 35 due to average stat rolls. If you don't get why, just think how you'd feel when you had a 65% failure rate at the thing you're supposedly best at.
this also means that you as the GM need to keep this in mind. If you want the players to succeed, either make it a group roll, give modifiers, or don't make it a roll at all. The system has means for random good/bad things to happen to people (charms, namely) and you can do a lot with that. Also, don't set things up where the player only has one or two chances to do an action or they fail/lose forever, at least not too often. They are likely to fail more often than not.
Tomorrow is friday, which is our normal Discussion day. I'll pick back up with System Analysis for Dark Heresy on Monday with going over Combat. Tuesday we'll go over gear, and that should wrap this up. Do you like this series so far? Requests? Changes you would like to see? Sound off in the comments.