Well, I'd heard about VP/WP before for years thanks to Star Wars d20, and then other games that used it. It just sounded like more recordkeeping to me, yet I was constantly bitching about how many hit points PCs were racking up in my D&D game and how unkillable they were, LOL. Then I switched to Conan OGL, and whjile it still had HP, it made a number of changes (Defense instead of AC, Armor becomes DR, reduced HP progression, Parry incoming melee attacks) that made combat more lethal and fun (scary). Eventually, last month I finally tried Star Wars d20, with its VP/WP mechanic (plus just about everything Conan had to offer except Parry). VP/WP were the answer I was looking for ever since 3e came out (and before, TBH). Combined with the rest of the rules changes, VP/WP make the game super deadly, super scary and super fun. Because you never know when you are going to die, or who's going to kill you! You ALWAYS need to be worried about getting into combat, because you could be 20th level and still get capped by some 1st level NPC class loser. So TACTICS become very important. You can't just charge 50 orcs (or stormtroopers) and expect to win. What you can expect is to be DEAD. So very, very dead. That's why nobody in their right mind ever does anything that stupid in real life or even in the movies (unless you're talking the end of Butch Cassidy and the Sundance Kid, when they KNOW they are about to die and decide to go down fighting). Cover (particularly in modern and sci-fi games) is your new best friend, because it reduces the chance your enemy has of confirming a critical. Critical hits bypass VP and apply straight to WP, and your WP are always woefully low compared to VP (at least after the first few levels; they start out higher because they equal your CON, and VP are only 1d6, 1d8 or 1d10 points/level + CON mod).
Now, here is a key element: NPCs without heroic character levels are mooks. They get no VP, no matter what level they are (unless they buy the Quickness feat, which weorks just like Toughness but for VP: +3 VP bonus). Most bad guy NPCs you encounter come in three flavors: 4th level (low level), 8th level (mid-level) and 12th level (high level). This makes them competent enough to maybe do something bad to you, but they die so easy because they have no VP. That is why stormtroopers and such wear armor. It provides DR, which
might let them survive one hit (if you roll bad for damage or are using a crappy weapon), but probably not two hits. They are there to slow you down. Cannon fodder. Like the movies. When you mix in villains with heroic character levels,, they have VP and many more abilities and they can tear you up right away if you're not careful. So when you see Darth Vader (20th level badass) walk up behind those three snowtroopers (4th level Thug - NPC class) that you weren't too worried about a second ago, you know it's time to get the hell out of there... Unless you've got a very good plan how to neutralize his butt. Quick. Just like the movies.
VP/WP causes players to pick their battles much more carefully because they can't just expect to win. Even minor fights can mess them up good when some mook rolls a crit and then confirms it. Critical damage multipliers are only ever x2; weapons may have greater critical threat ranges (such as 18-20). That's not to say the players will never get into fights. Just that they will be smarter about it. They have to be. Nobody wants to get into a pointless fight with VP/WP, especially Jedi or Sith. You gotta save your VP vs. damage and also to power your Force feats and skills...
The Force (magic in D&D) is powered by VP. Each Force power (magic spell) is a skill, but usually a tactical skill with various uses that fall under one umbrella. Each use of the skill costs VP, either a one-time flat cost per casting or a variable cost to maintain (depending on what you are trying to affect with it). This really forces Force-Users to think about skill point allocation, because they only get one set of points per level, so to master both mundane and Force skills, you gotta split your points between them. You either specialize or become a jack of all trades/master of none. Other character classes don't have this problem, but then again, they can't use the Force.
Force Points (aka Action Dice, Luck Points, etc. in other systems) are earned one per level and once per act of dramatic heroism. You can spend one once per round to add a a bunch of dice (depending on your level, and if you are calling upon the Dark or Light Side of the Force) to any d20 roll (skill checks, saves, attack rolls, critical threat confirmations). Different GMs may allow other uses. Personally, my villains use them to negate criticals on themselves.
Anyway, it's really not just about VP/WP; it's about a whole bunch of changes working together to make d20 more scary and thus more fun for both players and GMs. Once you get the hang of it, there really is not much extra in the way of recordkeeping. Remember that most NPCs don't even have VP to keep track of.
