No equipment: -10 for technological skills, -5 for other skills. Note that many skills cannot be used at all without equipment!
Improvised equipment: -5 for technological skills, -2 for other skills.
Basic equipment: No modifier. This is the case most of the time.
Missing important items: -1 per item.
Damaged equipment: -1 to -3.

Climbing Gear (TL2). Hammer, spikes, carabiners. $20, 4 lbs.