Definition of "Attack"

When a skill talks about an "attack" what exactly does that mean? For example in guardian you have a certain percentage chance of blocking an attack or projectile. Also in empathy when an enemy "attacks" they take damage.

Strikes at you with a weapon would be the definition I would use. Using a wand/staff/truncheon/etc would also count.

Attacks are basic attacks (like swinging your sword, shooting with the bow etc) and all skills that have Attack in their type (like Power Attack, Sewer Artery etc).
Projectiles are mentioned extra in the description of Guardian, as it blocks magical projectiles too (like Lightning Orb etc).

Yeah i have a few skills that say "attack or use skill" so that means that weapons and "skills" are separate. Skill of course being spells, but maybe things like final thrust, executioners strike and so on as well, not that it mattered with my particular skill.

In the same respect would it block chain lightning or obsidian flame? (Those are just 2 random elementalist skills)

Those 2 are not projectiles. They just magically cause damage, whereas lightning orb produces a projectile that flies and does damage if it hits (hint: you can actually sidestep it if you see it coming). That's one reason I prefer the chain lightning to the orb, even when I will only dmg one foe with it.

Ya, I like to think a projectile as just something that travels over time between yourself and the target.

So nothing instant, no firestorm, etc.

Ok, I can see that. But doesn't it also seem logical that some spells would also qualify as attacks?

Take Conjure Phantasm, for example -- as far as I can tell, there's no other reason to cast this spell unless you want to attack your foe. Sure, it does direct damage ignoring armour, etc. and is not a projectile, but all it does is attack (vs., for example, an attack that drains health but also returns energy to the caster).

As another example, I'm a R/Me, so I've got Lightning Reflexes and Distortion as defensive skills. LR states clearly that it helps you get away from [evade/block, I'm not sure what the difference is; the outcome appears to be the same] melee and projectile attacks, while Distortion merely says "attacks".

There's no question about whether LR can help you get away from spell attacks - it can't - but my impression from playing with the skill is that Distortion can. I think I can "evade" better with Distortion than with Lightning Reflexes. This would seem to indicate that at least some spells do qualify as attacks.

Anyone know for sure?