head to head
TERA asks more than Guild Wars 2, and the gap is execution.

Optimization · Practiced Mastery
Active dodge-heavy combat with a deep build system, tested against both scripted content and human opponents.

Execution · Practiced Mastery
A pioneer of action-MMORPG combat where skill-shot execution and precise dodges are the primary test.
Guild Wars 2 leans Optimization (Practiced Mastery); TERA leans Execution (Practiced Mastery).
TERA leans clearly harder on execution.
Guild Wars 2
Dodge timing and active combat define moment-to-moment play
TERA
Action combat with skill shots and iframe dodges is the core axis
Guild Wars 2 leans a little harder on reads, though the gap is small.
Guild Wars 2
WvW and structured PvP feature real adaptive opponents
TERA
Battlegrounds and large-scale PvP add a real but secondary reads layer
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guild Wars 2
Loot RNG is present but secondary to skill expression
TERA
Gear enchanting RNG creates frustrating hidden-information variance
Guild Wars 2 leans a little harder on optimization, though the gap is small.
Guild Wars 2
Build crafting and rotation theory-crafting reward deep analysis
TERA
Class rotations and gear progression paths are extensively community-solved
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.