While speaking about GURPS with other, non-GURPS players, I often hear the complaint that dice rolls in GURPS are boring. Since the action resolution system relies on 3d6 for everything, in most situation an average result can be expected. This page on Wikipedia gives all the details.
Why the bell curve?
Of course, many GURPS players find this is actually one of the nicest features of the system: it means that in average conditions, having a decent experience in a given fields pays off with regular success. This builds on how GURPS distinguishes raw potential (the basic attributes like Intelligence, Strength, Dexterity and Health) from actual training (the skills). Characters may rely solely on their potential and see some success from time to time, or they can work on turning some activity into their field of expertise, and remain confident that the more work they put into this activity, the more often they will succeed and the more chance they will get in achieving something under stressful conditions. This also means that under normal conditions, rolling the dice for an action the character has experience in will just act as a routine check of his level of expertise. Rolling the dice to see that, once again, Captain Brunch the hacker has once again succeeded in sniffing POP3 passwords on the local corporate network can get boring pretty quickly.
What other systems do
This differs greatly from some other systems, like Dungeons & Dragons. These games rely on a single die to resolve actions (the famous d20 in the case of D&D), which gives all results an equal number of chance to occur. This means that a roll has an equal chance, for anyone, to result in a critical success, an epic failure or anything else. An expert is as likely to completely fail as a novice and, on the other hand, a beginner can expect to have as many extreme successes as a veteran. This is, by no means, realistic, but on the other hand, it certainly brings some tension around the table when it comes to roll for action! This is key to the design of these games: we’re not in for dealing realistically with the world, we’re here to see heroes and beginners alike get rewarded dramatically, in a good way or a bad way, just for trying to do something. In other words, these games are on the pure game side of the spectrum, whereas GURPS can be found on the other end, on the realistic side of the spectrum.
Going all heroic
The question is: how can you bring GURPS from one end of the spectrum to the other, and have the players hold their breath each time they roll the dice?
Option 1: make each dice roll an important event
An easy option is to limit the frequency of dice rolls. It’s true that under normal condition, an unsurprising result can be expected. But why ask for a roll under normal conditions? It’s too easy to forget that dice rolls are for stressful situations, not run-of-the-mill skill checks. If they only get asked to roll dice in, well, dicey situations, the players are more likely to emotionally charge each little plastic cube. Suddenly, getting asked to roll the dice means that things are tougher than expected, and that very good or very bad things might happen.
Option 2: change the dice
Another option is to simply trade the 3d6 for a d20. GURPS scales skill and attributes levels between on the range 1-20 already. The ranges for critical successes and failures might need to be reduced a bit, e.g. from 3-4/17-18 to 1 and 20, respectively. Alternatively, a couple of d10 can be used for a good compromise between the flat probability distribution of the d20 and the bell curve of 3d6.