Friday, November 27, 2009

Over vs. Under

I seem to recall that in first edition Dungeons and Dragons, someimes you had to roll over a number, and sometimes you had to roll under. Today, all games follow a different trope, consistently requiring the player to roll over a target number. I'm not sure one approach is better than the other.

In 1e, you had to roll over your To Hit number in order to hit the target. This was a mathematical formula taking into account the opponent's armor class. For saving throws, which is a way to avoid monumental damage or horrific effects, you had to roll under a target value. Thus, if you looked into a medusa's eyes, and were about to be turned to stone, you rolled a save vs. paralyzation, using a number dependent on your class and level; let's say you had to roll under 10 as a first level character. Over time, your to hit number went down (making it easier to whack an orc), and your saving throws went up (making it easier to avoid being turned to stone). Those "target numbers" were a function of your character.

Nowadays, you always want to roll higher than an assigned value, for everything. This fits the trope that "higher is better". Jonathan Tweet specifically changed the saving throw mechanic for third edition AD&D to harmonize it with every other mechanic. He also ditched all the other rules that required you to roll under a target number, like thief abilities. I think, in general, this fits with human psychology. Players like to brag about how high their stats are, or how big a modifier they have, or jump for joy when they roll a really high number.

The idea is that rolling lower for success is counter-intuitive. And it's not just in AD&D. In Call of Cthulhu, every skill is represented as a percentage chance to succeed, Climb 40% or Drive 50%; you have to roll under this number in order to succeed at climbing or driving. I've played a lot of CoC, with a lot of different people, and no one seemed to have a problem with wanting to roll low.

Meanwhile, I think there's something to be said for having to roll under an assigned value. Sometimes, it just fits the mechanic, makes the math easier. Sometimes, it just feels right to vary the die rolling mechanic. I don't necessarily agree that it's confusing to require players to roll higher in some instances, and lower in others. I think it all adds to the flavor.

1 comment:

  1. FWIW, in AD&D a roll of 1 always fails a save, while a roll of 20 always make it, so you do want to roll higher than your target saving throw number (it reduces as your PC gains levels, just like your to hit rolls do). It was that way in OD&D and Holmes/Moldvay Basic too.

    There are a number of other sub-systems where you want to roll low vs. high, however: System Shock and Resurrection Survival are two examples (based on Con); others include skill/attribute checks (although they're not officially in the AD&D rules, per se); thief skills; MU learning spells percentages (a function of Int); etc.