One of the first things that I noticed while playing Guild Wars 2 was the significantly smaller number of possible skill combinations available as a character. To get an idea of the order of mangitude in the differences, I fired up excel and put together some simple equations:
For this estimate, I wanted to get a feel for order of magnitude (rather than an exact number) so I made some simplifying assumptions. First, I am looking only at the Mesmer profession in both games (since I am currently playing a Human Mesmer in Guild Wars 2 and my main was a Mesmer in Guild Wars 1). Second, I’ll assume that skills are evenly distributed across professions and attributes as that will make the math easier later.
Guild Wars 2
As a Mesmer in Guild Wars 2, I have access to 12 weapon combinations (staff, greatsword, spear, trident, scepter+focus, scepter+torch, scepter+pistol, scepter+sword, sword+focus, sword+torch, sword+pistol, sword+sword). Each weapon combination sets the first five skill slots. Next, slot six must be one of four healing skills (three Mesmer skills, one Human skill). Slots seven through nine are selectable from 22 utility skills (20 Mesmer skills, 2 Human skills) providing 1,540 (22C3) possible combinations of utility skills. Lastly, slot ten is one of seven elite skills (three Mesmer, three Human, and one Bonus).
Taking all possible combinations together provides:
Guild Wars 1
In Guild Wars 1, all skill slots are open. The only limitation is that you are allowed to have at most 1 elite skill and three PvE skills. At launch, there were 364 standard skills, 1 PvE skill (Signet of Capture), and 90 elite skills. They are approximately evenly distributed across professions, so I will assume that each profession has 60 standard skills and 15 elite skills. Since characters choose a primary profession at creation, and a secondary profession shortly thereafter, they would have approximately 120 standard skills and 30 elite skills available to them. Since Signet of Capture isn’t a very interesting skill to have on a build when you have all other skills available to you, I’ll assume that the two possibilities are whether to take an elite skill or not. If you don’t take an elite skill, the total combinations are 840,261,910,995 (120C8) ≈ 8.40 × 1011. If you take an elite skill, the total combinations are 1,784,627,067,600 (120C7 × 30) ≈ 1.78 × 1012.
Summing over both possibilities:
Comparison
The Guild Wars 1 estimate is a particular underestimate since you are allowed to swap out your second profession at about the midpoint of the campaign, but I think the main ideas are there. Specifically, Guild Wars 1 had (at launch) approximately 5 million times as many possible builds (without changing secondary professions) as Guild Wars 2. That’s not to say that all of those build were good or fun, but I think it leaves a lot more possibilities open for experimentation and creativity in builds at least.