We've received quite a bit of feedback on the mechanics we use to check for success with skills and spells in Netherstorm. Currently, there are two types of checks; uncontested and contested. An uncontested roll means rolling a check against a difficulty number given as chance of success. For example, if a character is trying to pick a lock, the GM may say they have a 40% chance. The character adds their skill levels and bonuses to the 40%. A character with 15 levels in Mechanics would have a 55% chance to succeed. The player would roll percentage dice, with anything 55% or less being a success.
The problem for most people is that contested rolls are the opposite. Because the character is rolling an opposed roll against someone (i.e., attack vs. defense, Stealth vs. Perception), the player wants to roll higher on percentage dice. If the character is trying to sneak into a room where a goblin is keeping guard, the player would roll and add a Stealth bonus, while the GM would roll for the goblin and add any Perception bonus. The higher roll wins.
Many people have no problem with the two mechanics for the two types of rolls. However, there are also many people who find it more complicated than they would prefer. After you've played Netherstorm a few times, it's pretty easy, but having the two mechanics changes the learning curve for new players. We've decided to implement the alternate mechanic below, to combine them into one mechanic.
Alternate Rule: Skill and Spell Checks
Under this alternate rule, opposed rolls work exactly the same. Roll, add bonuses and the highest roll wins. The change is with unopposed checks. Instead of giving the chance of success to roll under, the GM tells the player a target number that they need to roll over to succeed. In the example used above, the GM may tell the player they have to roll over 60% to pick a lock. The player rolls and adds any skill bonuses to the roll. If the roll is 60% or over, the character is successful.
The change to spells success is that, instead of having a base 30% chance of spell success, there is a base 70% target, which the player has to beat. The player rolls and adds the spell level and any other bonuses to the roll. If the total is 70% or higher, the spell is successful.
Having one mechanic for opposed and unopposed rolls should simplify things somewhat. Play around with it and let us know how it works for you.