You can in theory get reads at 25 ranks, 40 or so is the minimum I bother though, you can NEVER see an incorrect value, you can however see nothing or that its weighted/padded with no quantity givn. it becomes mostly reliable and 1 or 2 tries at 50 ranks, oddly temporary padding or weighting seem harder to assess then permanent. Haven't assessed enough items with both critical and damage to know how that influences difficulty.
Khaladon starts to turn the crystal knob, but stops with a frightened look on his face. He begins shaking uncontrollably and flies across the room, as though by some invisible force.
**SPLAT!!** Khaladon careens off the far wall, slides down the smooth wood panelling and collapses into a quivering heap on the floor, with only his dignity bruised.