About a month ago I presented a percentage-based skill system that converted all the x-in-6 chances from OD&D and what I used in their d12 conversion for Onn Core Rules. Having been playtested by a friend of mine, Tom, and his gaming group for the last month, here is the refined system:
- Characters begin play with a base score of 8 + the character's relevant ability score + any additional adjustments (such as racial adjustment) = the base % chance of success.
For example, Cedric the Elf Magic-user has an Intelligence score of 16. His chance to Detect Hidden (secret doors and the like) is 8 base + 16 Int = 24%. Because he is an elf he gains an additional +10% to this particular skill for a total of 24 + 10 = 34%.
- When a character advances each level beyond 1st level, he adds 3 + his Intelligence adjustment and multiplies the result by 5. This number is the amount of skill points he can distribute among his skills as he sees fit, so long as no skill recieves more than 10 points.
For example, Cedric reaches 2nd level as a Magic-user. He gains 3 + 1 (Int adj) = 4 x 5 = 20 points to distribute among his skills. He decides his Detect Hidden has been very useful and allocates 10 points to it, raising it up to a 44% and distributes the remaining 10 points into his other skills.
- [OPTIONAL] The Referee or player keeps track of how many times the characters use their skills successfully and relevantly for the game session. Once per session a player may declare he is trying to improve the skills a character has successfully used. For this roll, the player attempts to FAIL the skill check (rolling higher than their chance of success) and gains a +1 bonus to the roll for each tracked use of the skill being improved. If this reverse check is failed, the character gains a permanent +1% to their chance of success. Succeed or fail, the player wipes all tracked uses out and begins tracking anew.
Our elf Cedric's player decides to start tracking his character's skill uses with the Referee's approval. A couple hours into the session, the party hits a dead end and according to their mapper must be at the location of a secret door (based on what they found previously). Everyone in the party fails to find it. Cedric's player declares he is thinking back to all of the lessons his mentor taught him on how to stay safe and find very hidden things. The Referee tells Cedric's player he has 4 relevant skill checks for Detect Hidden so far and the player casts the dice against his 44%. He rolls a 41% and adds his +4 for his 4 relevant uses so far for a total of 45%. Failing the check, he gains a +1 to his chance of success in the future and is granted a reroll with his new score of 45%.
Typical use of this system is rolling equal to or under your chance of success (just like using Thief skills in older editions of the game). Onn doesnt have Thieves though, so this system also doubles for those players that likes those percentage dice.
NO SKILL SYSTEM SHOULD EVER DICTATE THE FUN YOU ARE HAVING!!! IF A PLAYER GIVES YOU A THOUGHTFUL EXPLANATION OF SOMETHING COVERED BY SKILL USE AND YOU CAN'T SEE A REASONABLE EXPLANATION WHY HE SHOULD FAIL, THEN DON'T ROLL THE DICE! One trap is to over use the dice and make skill checks for everything under the sun. Some games run fine this way, but don't change your playstyle to accomodate a system...adjust the system for your playstyle.