This post is oudated, pre-release. Read later posts for newer stuff.
The following concerns PvE.
A common complaint when it comes to PvE for many MMOs is boredom stemming from dull or repetitive combat, especially while leveling. GW2 has 1-upped most MMOs in this regard with its dodging and weapon-swap system.
Still, two problems exist -- and one is for engineers:
1. Builds focused on stat boosters (e.g. +10% power) or simple random procs (e.g. 33% chance-on-crit to burn) are great for DPS, but they aren't very dynamic -- which can lead to repetitive combat.
2. Engineers don't have weapon swap. We have kits. You can avoid kits and still have a great DPS build, such as dual-pistol/elixirs, but this may make for very simple and possibly boring combat. A turret or gadget build would be my non-kit alternative if I wanted something dynamic.
Ultimately the choice is yours. You should play how you see fun. The greatest way to fight combat repetitiveness is to change builds often and try different things. Until ArenaNet implements a on-the-fly multi-build system many people will be hesitant to do this during PvE.
For now, my recommendation for the most dynamic and fun Engineer build is the QUAD-KIT build. Let's go!
HOW IS IT DYNAMIC?
First and foremost, having 4 kits. I recommend Elixir Gun and Flamethrower, and one of Grenade Kit or Bomb Kit -- whichever you prefer. You could adjust the build if you're in love with the Tool Kit. The principle is 4 kits. This gives you a tool for every scenario, and that is what Engineers are all about. The strength of kits is that, unlike weapon-swapping, there is no recharge and only a global cooldown of 500 milliseconds.
As for traits, in my opinion traits are dynamic when they aren't random procs or stat increases. They're traits that enhance your combat more kinetically. They may reduce the recharge of your skills, increase the radius of your explosions, allow pistol shots to pierce, allow increased attack range, or even create a dynamic spell upon using another skill. When a trait influences your fingers to press more varied keystrokes, it's doings its job to give your more dynamic combat.
Every trait I just mentioned is included in this build. This build has no traits that are stat increases or random procs. All these things work together to bring you a more rapid and flavorful combat experience.
For dual pistols or pistol/shield:
(Same build for pistol(s) but swap Rifled Barrels for Coated Bullets -- it's just too good)
You could make an argument that Coated Bullets, further attack distance, and larger explosion radii aren't that engaging, but I think they create a chain of combat events that are more interesting and affect gameplay more dynamically than simple random procs or stat boosters. I emphasize simple procs because some procs can be very dynamic, but they're found mostly on sigils or runes.
Why Kit Refinement? This is a fun but also powerful kit trait. Every time you equip a kit a spell happens. Seeing how you have 4 kits, this will happen often. Not just some minor spell mind you, these spells are mirrors of your skills and equally damage-worthy: http://wiki.guildwar.../Kit_Refinement
What about the elite skill? Honestly anything goes here. The idea behind QUAD-KIT is versatility, and most our elites provides versatility. Elixir X, or a race's elite such as Charrzooka, are most akin to our kits because they provide a new skill bar for whenever the situation calls. The elite skill is not as important for this build so select what's fun or optimal for you. As a Charr I will probably toy with Charrzooka because it's most like a kit. (Don't read into that too much, it isn't a kit and benefits none from our traits)
WHERE TO SPEND POINTS WHILE LEVELING?
I recommend this route for rifles:
Tools (Kit Refinement) → Firearms (Rifled Barrels → Hair Trigger → Fireforged Trigger) → Explosives (Forceful Explosives → Short Fuse → Grenadier)
This is important: you might be wondering why Kit Refinement and Rifled Barrels are lower than the other adept traits. It's all about conditioning. Leveling is a great way to learn your profession. If you pick up traits that give longer skill ranges when you're at end-game, you have to relearn your distances. If you start from the get-go with these traits you will be well conditioned by end-game.
Kit Refinement is similar. It will condition you to swap your kits more often when you see how neat it is to get those extra skill spells for free. (just don't swap kits whenever for the sake of Kit Refinement though).
Pistols is the same except your Firearms path is straightforward since you'll forgo Rifled Barrels for Coated Bullets. In my opinion trait selection for this build works like this (in order of importance):
Weapon Piercing Traits → Multi-Skill Recharge Reducing Traits → Increased Ranged Multi-Skill Traits → Increased Radii Multi-Skill Traits
Generally speaking, using kits early on will condition you greatly. If you go pistol/pistol elixirs the entire game and only look at kits once you're 80, your head might be in for a spin. In the reverse, picking up pistol/pistol elixirs at end-game as a QUAD-KIT veteran will feel like a 300-pound barbell just got lifted off your back.
The number one hurdle to this build, that I don't really see as a con, is its learning curve. You will have more skills ready at your fingers than any other profession. Not only will you have an enormous arsenal of skills, but every weapon's recharges (except Shield) and kits' recharges (except Med Kit and Tool Kit) are lowered through traits. There won't ever be a second that you are left wondering "Damn, I'm in a tough situation with nothing to use!" or "This combat is so repetitive!"
Like said, the learning curve will be steep. Incredibly steep actually, considering how quickly you can get kits while leveling. You'll have most if not all of them by 20. Due to this build's key-binding potential, I'd say QUAD-KIT engineers will be the least popular but the most rewarding in fun combat.
The next con ties into learning curve: Staleness. How does a QUAD-KIT build ever become stale?! By not actively swapping your kits when the situation calls for it. If you get too comfortable and lazy with a kit, you may feel like you should never swap kits. At this point this build is either not for you, or you need to step up your game!
The last noteworthy con is the sustained DPS may not be on-par to min/max builds. However, this build at level 80 will still have very good DPS with all those points in power/crit and 10% critical-damage from tools, and let's not forget shorter recharges all around.
This build received a solid recommendation from the Law Offices of Saul Goodman. "Better Call Saul!"
Edited by Zenh, 10 September 2012 - 08:56 PM.