Skill System in Mongoose Traveller RPG

It seems like every one and their dog are writing about skills in D&D since Monte Cook started talking about them in his new Legends and Law column at the WotC web site. There's been lots of talk on twitter about it too. If you want to know people's thoughts on the future of D&D skills then some of the blogs I link to on the right are likely to have a thing or two to say about it. All the chatter has made me pretty much shut off from talk about the future of D&D, I'm way past the point where the speculation is interesting and I want to look to different things until it all blows over (luckily it's Play a New RPG Month soon so it's easy to do that). However it has got me thinking about skill systems in other games and how I feel about them. So I'm going to talk a little about one of them and see how they compare.

I'm enjoying playing Mongoose Traveller at the moment, a science fiction RPG and I am a big fan of the skill system that it uses. The skill system is the heart of the game and if you want your character to do anything that they would not automatically be able to do you need to roll a task check. This includes spacecraft operation, combat, arguing a case in court, looking for something, researching an alien species or making a deal for some cargo. The mechanic is that you roll 2d6 and add the appropriate skill modifier and the appropriate characteristic modifier then you add any dice modifiers and compare the result to 8. Above 8 is a success, below is a failure. Keep track of how much you succeed or fail for a lot of situations. As a referee I'm particularly interested in how badly you've failed for consequences purposes.

For example if you are trying to fix a piece of machinery that you've never seen before I might ask you to make a Mechanic check. So say you have 1 rank in mechanic you would add that to your roll. What characteristic would you use? Well in Traveller there are two characteristics that might be appropriate here, Intelligence and Education. Which to use? It would depend, in this situation, on how the player would want their character to approach it. They are likely to want the biggest modifier but it would be best if they can justify that. For instance if they wanted to use Education because that would give a +2 bonus then they could say that they are using their training with a similar type of machine to work out how to fix this. If they succeed then they can describe how it turned out that this machine had a part very similar to what they were used to dealing with and it just needed replacing. If they fail then it could have been that they thought they saw something they understood but it worked in a completely different way to how they were expecting and now the machine is useless.

The most complicated part of the skill check is the dice modifier. It's basically a way to change the challenge of the skill check. For instance it's suggested that for a simple task you should add a difficulty dice modifier of +6, an easy +4, routine +2, difficult -2, very difficult -4 and formidable -6. You can get +1 for taking longer over the task, or sacrifice -1 for rushing. Situation modifiers are +1 for things that might work for the character such as decent tools, clear weather or assistance from a robot, or -1 for things that might work against them like having to perform surgery in a muddy field in a storm with only a butter knife. These modifiers add and subtract to each other to give you the base likelihood of anyone being able to succeed in the situation where as the skill rank and characteristic modifier add in your characters likelihood of succeeding and then you roll the dice.

The mechanic works very well for a RPG that is focused on characterisation and the skills that characters can bring to the table. A character that is untrained in a skill and attempts to use it takes a -3 modifier to their roll so would be unwise to attempt any task of any but the most easy difficulty so it pays to have people with different skill sets work as a team. Characters with overlap in their skills can work together, there are rules for assisting, and everyone gets a chance to shine.

Having a single +1 can mean a lot on a 2d6 roll. The numbers on the dice are more likely to be in the 5-9 range so any advantage you can get will help. Having a total dice modifier of 0 gives you a 42% chance of succeeding but that is up to 58% for +1. As such the Mongoose Traveller rulebook suggests that having a +1 in a skill means that you are competent at using the skill, you could easily get a job doing that. If however you have a +2 you are likely to be high up in your field, +3 at the top of your game and +4 an almost unique practitioner. If you have +3 or +4 then you probably want to incorporate the reasons for that in your character background (driven by how you proceeded through character creation, another area of Traveller I love). Characteristic dice modifiers usually range from -2 to +2 with 0 and +1 the most common, characteristic generation is random but I'm not going to force a player to keep a -2 DM if they don't want to.

This pretty much means that if a character is notably good at something them under normal circumstances they will probably succeed at doing it. This is helpful in a game like Traveller when a pilot is trying to land the ship under ideal conditions. Combat however is a bit more complicated in that there are a lot more dice modifiers that are likely to apply for things like cover(-), aiming(+), dodging(-),owning a smart weapon(+), firing into fog(-), and inappropriate range for weapon(-). Things can get away from you fast in a fight, but still professional soldiers are likely to still be able to hold their own (it often comes down to differences in equipment in combat for people with high skill levels).

Overall I like the task resolution system in Mongoose Traveller. It's great for the style of game. I have heard that the designers had some great ideas about both dices having special meaning but that got cut from the game before release. I don't know how true that is but the clean system left is a good one. It works well for a normal, but trained, Joe type of character. This is different to the D&D style D20 system that works well for the epic hero but with large variance in the outcomes to add tension.

I was also thinking about writing about the World of Darkness skill system as a dice pool example to contrast with the roll plus modifier one here but I got a bit carried away by Traveller because I enjoy it. Does anyone have any other non D20 skill systems that they love that I should know about? I can think of the dice type per rank of Savage Worlds or Cortex+ games and the Jenga tower of Dread and some people have had good things to say about Legend of the Five Rings but I've never played it.