nats said:
So what I am asking is how would you Referee this little obstacle?
A suggestion as a GM:
Never make your players do anything that requires die rolls unless you are prepared for what happens if they fail.
Tabletop RPGs are a group activity; it's always more fun to play some first-person video game if you just want individual coolness. Try and aggregate success and failure across the entire party instead of singling out individual characters if at all possible.
It feels natural as a GM to make a player roll to scale a cliff. But what happens if the player fails the check? If the player dies from scaling a cliff, is that fun for your player or you? Will this enhance the fun for you and your players? If not, you might want to reconsider the consequences or the need to make a skill check at all. For instance, even if you go down the less lethal route and on a failure, the player falls and breaks a leg (for instance) how does that contribute to the adventure you're running? Or did you just force the entire party to withdraw to get the injury treated or will the player have to sit out the rest of the adventure at some camp? Did that enhance the game?
Traveller with its vaunted (?) 2d6 skill check system has an extremely high chance of failure; in fact the failure rate is so high it cannot model many real-world situations. Assuming you will fail on at least a total of 2 on 2d6, that's a 3% failure rate (actually it's like 2.77%). Often it'll be much higher, making games like Traveller ill-suited to playing truly skilled characters (for instance, to qualify to be a sniper in the more demanding real life militaries today is impossible with Traveller's skill system). It's a limitation of the 2d6 system.
What this means as a GM is that you should only make your players roll skill checks in situations where there is a high chance of failure (higher than 3%). Many potentially risky tasks should not be rolled at all if you don't want them failing. For example, it's pretty routine to make the pilot of a starship roll to do something like Gas Giant refuelling. What happens if they fail? Do 3% of all starships trying to refuel in a gas giant fall in and get crushed? How about 2%? 1%? Even a 1% failure rate would be so suicidal nobody would do Gas Giant refuelling if it meant that 1% of all the ships that try it run into some complication and are crushed like a bug as they fall into the Gas Giant. Nobody would do such a ridiculously hazardous thing. To use an example from the real world you might be better able to relate to, the rule of thumb with the chance of a parachute failure during skydiving (assuming you're using a professionally packed chute) is 1 in a 1000 (0.1%). If you pack a reserve chute that chance drops to 1 in 1000000. Yet most RPGs require you to make a skill check, usually with fatal consequences if you fail for parachuting. In Traveller, if you forced a die roll for the parachute opening, you could never hit 1:1000. It'd always be 1:33. Although parachuting sounds like it'd be risky, I wouldn't require a die roll for it - most die-roll systems just can't account for anything less than 1% failure rate.
So back to the idea of scaling a cliff. I'd only make them roll if you're:
* Doing simulationist timekeeping. Some GMs do this. Many GMs don't. They figure out when the players set out, how many hours of daylight they have, tracking player fatigue levels, and so on. The cliff is not necessarily a fatal obstacle, but a time waster. Everyone makes a roll. If it's utterly ideal (all the players succeed) they the cliff scaling incurs no additional time; its as if the cliff didn't exist. Each player who fails means they spend an additional 1d6 x 10 minutes scaling the cliff; this does not mean that a particular character fails, it just is an aggregate of the trouble the cliff gives them as a group; perhaps it is very windy and they spend time waiting for the wind to die down or one character who failed basically loses his or her nerve and the other players work out a method a lift the character up on a rope - it takes time to prepare the rope and so on.
* The players are under imminent threat. The players are running at full tilt, pursued by an enemy. The players come to a cliff on the side of the road they're fleeing and decide the best way to shake their pursuers is to climb up it. They're in a hurry, the enemy might show up at any minute. Sure, by all means, the players are under intense stress, they may be tired, and so on. It's part of combat as far as I'm concerned. If everyone succeeds, the players successfully shake the enemy who continue to pursue them down the path or whatever they would have taken. If one or more characters fail, then any other character who succeeded on the check with a success that would have qualified for the next higher tier of success may "lower" his or her success to help the failing character move up to a normal failure. If a successful player scored particularly well, the player can boost up the failing character's result even into success by dropping his or her own success down to bare level necessary to succeed. This simulates more skilled or lucky characters helping those less fortunate from falling or just helping them out in various ways.
This incentivizes players to take a variety of skills and reinforces the group nature of RPGs - the player who took Climb-4 feels useful now, not just for him/herself but can extend the benefit to the rest of the party. After all of this, if there are still one or more players who failed, the enemy get a perception check to see if someone actually looks up to notice some evidence of the party's action: They might notice the last character just vanishing out of sight, or they might notice the climbing ropes still dangling there that the party didn't have time to gather up; regardless the enemy are aware of the misdirection and will react to it. If one or more players are still in a state of critical failure, they don't fall, but are still physically on the cliff face when noticed. The enemy will automatically hit these vulnerable characters with ranged weapons unless the other party members can provide covering fire with any ranged weapons they have.