Partly updated for Enshrouded 1.0— 1.0: the unlock cost; the rest is pre-1.0 wiki data

Opportunity
The pre-1.0 wiki text for this skill gives numbers the 1.0 files changed, so it is not shown; the 1.0 values are above.
Where Opportunity sits on the 1.0 tree
In the Core area. The cheapest way in from a starting point buys 2 nodes for 2 points, this one included (one rank each).
Builds that use Opportunity
1 preset build tagged OPPORTUNITY — defining picks first, then ranked by tier (S → A → B).
Related Survivor skills
Same archetype — likely candidates to slot next to Opportunity in a build.
Fisherman's Resolve1pIncreases your Fishing Endurance by 30%. Allows for extended battles with hooked fish.
Lumberjack1pFelling axes do 30% more damage against wooden objects including trees.
Mason1pThe Pickaxe deals 30% more damage against stone objects, including resource veins.
Power Parry1pEnemy Stun Bar gain from parries is increased by 30%.
Quality Gear1pValues in the 1.0 files: 20%.
Saviour1pYou only need 3 instead of 6 seconds to revive an ally.
Well Rested1pThe base duration for the Rested buff is increased by 5 Minutes. Increase the Comfort in your home to further increase the duration.
Backstab Damage2pIncrease the damage you deal from behind by 25%.
Sources: game files 1.0 + Keen Games 1.0 patch notes (changelog, combat changes) for the unlock cost; enshrouded.wiki.gg (pre-1.0) for the description and effects.