Skill challenges provide a great opportunity for a unified travel mechanic.
Travel is almost always a bit of a problem in tabletop role-playing games. Should we handle it by skipping over it, as frequently happens in movies? Should we make our players tells us who is keeping watch each night? Do we just give a highlight reel to cover the most interesting parts of the travel? There is no one correct solution to the problem, but I have found one that I enjoy and use in my home games.
Begin by dividing the travel into regular segments. Days of travel are a common choice, but you can use whatever feels appropriate. Since my home game takes place in the Birthright campaign setting, I track PC travel by province, with each province equating to about one to three days of travel, depending upon the terrain.
For each segment if travel, give the party an opportunity to pass a very simple skill challenge. Each player gets one roll for the segment, and the party as a whole must pass three different skills with DCs as shown on the tables below.
If the heroes pass the skill challenge, then they move though the segment without incident. If the heroes fail the skill challenge, then trouble finds them in whatever form you, as the DM, feel is appropriate. The system is quick, easy, and allows for some role-playing of travel without addressing every aspect of the journey.
The thing that separates this skill challenge from others is that you should not change the DCs as the heroes increase in level. As the heroes gain power, travel should become easier for them. A highwayman that might try to coerce a green party into giving up their gold will steer clear of the same adventurers once they have more experience. Terrain that once was challenging can be easily crossed through magical powers or sheer tenacity. Cities are easier to navigate when the peasantry falls over themselves to help the party. If a player is guaranteed to make a roll, then do not force him or her to make it. Some parties will be able to automatically cross friendly territory without incident starting at level one, and higher-level parties will find challenges less and less often. Come roughly eighth level – which is, conveniently, the level of the Linked Portal ritual – travel problems are virtually non-existent. The unchanging DCs of the skill checks mean that the players can really feel their characters growing in power and maturing as adventurers.
The thing that I really like about this mechanic is that it gives the world some sense of danger for low-level parties, but it slowly fades from view as the party levels up and moves on to bigger and better things than the goblins outside their village. If you really like the mechanic, it is not at all difficult to reintroduce it when the heroes travel to completely new lands or planes of existence. Drop your eleventh level heroes into the Feywild or Shadowfell, and they can experience the dangers of travel all over again, with increased DCs to correspond to their level. If your eighth level PCs enjoyed finally being able to cross the frontier with relative immunity, they could get a real kick out of doing the same in alien lands at a higher level.
Playing out travel in an interesting, concise way is difficult in most game systems. The above system might be what you need to make it work in your game.
How do you handle travel in your game at home? Does it changes based on the setting, or do you use a unified mechanic? How would you do this differently in a game set in a world with more extreme conditions, like Athas?