Challenges (Challenges International, Inc. 1986) describes itself as an "Easy-to-Play Game System for Fantasy Roleplaying, but in reality it is more of a slimmed down, modified version of D&D/AD&D. Tom's system mostly covers character creation, which is very similar to AD&D, along with some spells and brief notes on how to interpret monster write ups in "any of the various fantasy roleplaying adventure modules published by Challenges International, Inc". As far as I can tell, CI only ever released one adventure, Seren Ironhand, though the notes in the rules can apply to any D&D or AD&D adventure with little modification.
It's Tom's modifications to character generation that interested me most, and that's what I'll be addressing here.
Most of the material here would be familiar to any AD&D player, but since Tom is also more notably the co-creator of the BX edition of the D&D Basic rules along with Dave "Zeb" Cook, I got to thinking about applying the modifications in Challenges to that, and other, incarnations of Classic D&D.
Tom's method for generating ability scores is interesting, if a little overpowered for my taste. He suggests rolling 2d6+6 nine time and choosing the best 6 results, which are then assigned to the abilities as the player wishes. Obviously this will create characters who are a likely to be more powerful than their standard D&D peers, but the option is there if you like it.
Next we get to the suggested Ability Score Adjustments; that is, the game effects for having a high or low score in each ability.
At first glimpse, you'll notice that some of the standard D&D terms are changed, probably to play nice with TSR. Reading into the text though, these changes are common sense.
Warrior = Fighter
Sorcerer = Magic User
Muscle = Strength
Will = Intelligence
Stamina = Constitution
I included the chart for reference, but it is obviously formatted for AD&D, with percentile ability scores. I don't intend to bother adapting that AD&Dism to my Classic game, but the notes below the table are interesting, and could be applied to Classic D&D characters in order to reward high prime requisite scores without unduly harming game balance too much.
In all cases, these bonus adjustments are in addition to those those listed in the Basic Rules, so yes, a fighter with 18 STR gets +4 to hit and +5 to damage, total, but he's a fighter and has no other special abilities, so is it really that outrageous to ensure he has a slight edge over the lucky Cleric of Thief who rolled an 18 for STR also?
If you intend to use this chart, I'd ignore the Basic rules-as-written, and grant these to hit and damage modifiers only to fighters (Warriors), including Dwarves and Halflings, but not Elves. This actually appeals to me because it gives fighters a noticeable advantage in combat over the other classes.
Magic Users (Sorcerers) would instead get a couple bonus spells per day added to their arsenal, thanks to a high Intelligence (Will) score, which can give them a little better chance of survival at low level, and since they only include 1st and 2nd level spells, the long term game balance isn't really impacted too much. To give the Magic User some advantage over the Elf, I'd restrict this ability to Magic Users only. Note: A Magic User still can't cast 2nd level or 3rd level spells until normally allowed to through level advancement.
Alternately, if the Elf players complain too much, you could allow them to choose one of the two bonuses, either STR or INT to use, but not both. This actually has some precedent going back to the Original D&D rules, where the Elf player had to choose between the Magic User or Fighter class, but not both, for each session of game play.
Likewise, Clerics can pick up an added spell or two per day if they have a high Wisdom score, which usually ends up benefiting the entire party in the form of extra healing, so I don't see a major downside. A Cleric still can't cast 2nd or 3rd level spells until normally allowed by class level, but the decision of whether to grant a 1st level cleric access to her bonus first level spell is up to the DM. I allow, since, like I said before, it tends to help the entire party, but I can see how some rules purists would prefer the Cleric wait until 2nd level to cast any spells, as Classic D&D says.
The Thief options require a little definition:
Skill Bonus applies to Open Locks, Find Traps, Remove Traps, Pick Pockets and Climb
Stealth Bonus applies to Move Silently and Hide in Shadows
What do you guys think of Tom's ideas for more "advanced" characters?