Something I’ve been asked about a few times is why Other Worlds uses one 50% supporting ability and then a bunch of 10% supporting abilities. Well, it may look like a bit of unnecessary complication but it’s actually really important to the mathematical functioning of the game.
The reason is that it allows flaws to operate on the same kind of ratings as normal abilities. Which in turn enables you to have one unified, easy-to-remember system where all abilities (positive and negative) affect conflicts in exactly the same way, often switching over from positive to negative modifiers during the session depending on the circumstances of each roll. This was one of my big design goals when writing the book.
If all supporting and negative abilities only modified things by 10%, you’d have to give flaws massively high ratings for them to even make a dent. So you would have something like Broken Leg 100, but it would only give you a penalty of -10 when you tried to run off somewhere. Not to mention you’ve now got a huge rating to beat when you want to try to heal the thing. Further, if you then found a way to turn your flaw into a benefical trait (eg using your broken leg to get sympathy from a trader), the resulting bonus would be so high it would dwarf everything else you had.
If all supporting and negative abilities modified things by 50%, or even something more midrange like 25%, you’d have the problem where having multiple relevant abilities becomes much more important than the main ability or even the dice roll itself. This after all is one of the reasons that the game uses a d100 – to accommodate lots of little modifiers based on the character’s culture and personality without letting them dominate. Having more relevant mid-rated abilities than the other guy, or fewer applicable flaws, would start to decide conflicts in itself. I think the game works best when conflicts have room to surprise us and the underdog still has a decent chance at victory.
Another option would have been to use the rating of the flaw itself as the opposition number. That sort of works mathematically, but it also pushes the actual opposition in the conflict right into the shadows. Whether you’re fighting the evil Baron Whatsisname or trying to climb over the Great Fortress Wall of Quan-Ting is sort of just flavour, because what you’re really rolling against each time is that Broken bloody Leg. That wouldn’t sit right with me.
The 50%/10% also has a nice effect on ability use in general, making it harder to rely on one single very good ability and emphasising the importance of relationships and personality traits that can be applied to lots of different situations. It also helps stop the ‘augment trawl’ familiar to players of HeroQuest by communicating clearly to players that the second and subsequent supporting abilities are cool but don’t really matter all that much in the grand scheme of things.
If anyone has any other questions about the design decisions I made for Other Worlds please let me know and I’ll try to address them in a future post.