I was writing an adventure the other night and one of the challenges requires some combination of navigation, survival, region law, tracking or at the very least general perception.
The characters have an option of paddling up a jungle river with its inherent risks of crocodiles, water snakes and possibly hippopotami.
The could of course use the well worn track that edges the jungle. Then they face the threats of solitary big cats, snakes and wild boar.
Additional threats are also impoverished humanoids who have been outcast from their communities.
The point is that there is a lot that the characters may want to avoid or at the very least be aware off and not stumble into. The adventure is expected to be a second adventure for relatively new characters so they will have an additional level under them or if not then this journey will be enough to level them up. Just reaching their destination will be a story point for experience purposes.
I had always assumed that Perception was about THE most basic of skills. I saw on a discord server recently a discussion about leveling up and the advice was not to bother with Perception unless you were a Rogue or such. In my games Perception is probably the most used skill.
Something else I have always done is shift the difficulty factor if the character doesn’t have the ‘right’ skill. So an Easy tracking roll would be a Light Perception. A Medium Navigation test would be Hard Region Lore. If you don’t have Navigation or Region Lore and you are just relying on Perception to keep sight of the track or spot the right tributaries then that would go from Medium Navigation to a Very Hard Perception test.
Using this graceful downgrading it both rewards characters that have build a broad skill base while not making tasks impossible to beginning characters who may not have all the skills they would want.
I know this breaks the RMu similar skills rules. That uses a 0/-25/-50/-75 progression and combines two penalties so that the penalties mount up really quickly. Look at this example from A&CL.
Example: Perception and tracking are in the same
A&C Law page 47
category, but different skills, giving a -50. They share
virtually the same techniques, as well as a similar
subject (the environment). The total penalty to use
Tracking in place of Perception, or Perception in place of
Tracking, would be -50.
My method is much kinder on low level characters and a two step penalty often means just a -20 penalty. For higher level characters the risks tend to be higher and the challenges harder so that -20 turns into a more likely -40 as your more likely to hit Sheer Folly and harder.
It is also easier to work out on the fly. The greater the degrees of separation between the skill the character has and the ideal skill for the challenge then the more steps in difficulty. This eliminates another table lookup to boot.
It also makes it easier to write adventures where to do not know the level or composition of the party.