Skills over 100

A rules patch for Mongoose RuneQuest

### The Problem

The current rules state that in an opposed skill test,  if one character has a skill over 100% then both characters should halve their skill for that test. This continues untill both skills are under 100%.

Consider a character with a skill of 100% versus a character with a skill of 20%. The character actualy has odds of wining of around  93%.

Now consider a character with 101% versus a character with 20%. Both characters halve their skill, so for this contest the scores are 50% versus 10%. The higher skilled character turns out now to only have a 62% chance of winning (this is partly due to the rule that lower roll wins if both characters fail, which the more skilled character now does half the time). His chance of winning has fallen by one third!

Another problem is that in the basic MRQ rules, the best success you can get in an opposed skill test is a plain success. Critical successes are not possible. You may not consider this a problem.

### The Patch

For characters with a skill chance over 100%, roll D100 against their skill, ignoring the hundreds column. e.g. for a character with 230%, roll against 30%.

Next, for every 100% the character has (every digit in the hundreds column) upgrade their level of success by one. e.g. For the example above if the player rolled 64% (a fail) this would be upgraded twice, to a Critical success due to their very high skill level.

In Opposed Tests, the character who rolls the best level of success wins. If both roll the same level of success, then they score a draw and may re-roll the next turn.

For every level of success the loser has, degrade the level of success of the winner by one. e.g. if your opponents scored a success and you scored a Critical, your result is degraded by one level to a plain Success. A fumble actualy improves the level of success of your opponent by 1 level of success.

Note: A character's chance of a critical should never be less than the skill divided by 10. Thus a character's critical chance is the higher of (skill /10) or (skill - 100).

Using these rules, successes better than a Critical are theoreticaly possible, when skills go over 200%. e.g. A character with 205% has a 5% chance of a 'Super Critical'. Such results are retained for comparrison purposes, but the actual game effects are never better than a Critical success.

Example: Consider a character with a skill of 140%. The player first rolls D100 against a score of 40%, and rolls 02 - a Critical. This is upgraded to a 'super' critical by the automatic upgrade due to having a skill over 100%. The character's opponent rolls 44 against a skill of 80% - a plain success. This success degrades the first character's result to a Critical, which is the final result.

In combat, the simplest approach is to use the combat table as presented in the MRQ rules. MRQ combat doesn't use the skill contest system anyway.