Traps, Disarming:
All traps will be given a difficulty rating of 60-200 (some traps will even have a higher difficulty rating than 200, but these are rare, and are to challenge the best of the best).
The G.M. will often create his or her own trap and set a difficulty rating on it (this is a common practice). See: "Traps, Random determination of:" in the T section of the Basic Rules Book.
To determine the success of disarming a trap depends upon a thief's skill, calculated as follows:
Dexterity + Intelligence + % roll (1-D100).
This is how it works:
A thief will add his or her Intelligence and Dexterity together. Then a % roll (1-D100) will be added to the score.
Example:
If you have a 30 Dexterity, and a 25 Intelligence, your base trap disarming skill will be a 55. Then you roll 1-D100 and add the 55 to the roll. If you roll 27, you would then add the 55 to it (55 + 27 = 82). You would be successful at disarming a trap with an 82, or lower, difficulty rating. It's that simple. Make sure you read the "Note" below.
Notes:
1: As is the rule with missing with a weapon in combat, a roll of 01-09 will always indicate
failure in disarming a trap (unless, of course, a character possesses a certain item, or
special ability to increase the chances of success).
2: When you fail to disarm a trap, it will be set off.
3: One can only disarm a trap if the ability, "Disarm Trap" has been learned. If you do
not have "Disarm Trap", you cannot do it.