Simple 1d6 Skill Checks

STR Athletics, Acrobatics, Lifting, Rough wall climbing (not smooth - thief skill only)
DEX Acrobatics, Sleight of Hand, Stealth, Walking on ice or an edge, Tying a rope quickly, Lighting a torch quickly
CON Holding breath, Endurance, Nausea
INT Arcana, History, Investigation, Nature, Religion, Scribing, Reading
WIS Animal Handling, Insight, Medicine, Perception, Survival, Nature, Tracking
CHR Deception, Intimidation, Performance, Persuasion

3rd, 6th, 9th and 12th level
You can increase the odds of any one stat skill by 1. For example if your DEX skill started at 1/6, at 3rd level you can make it 2/6. At 6th level you can increase it again or, increase a different stat skill by 1.

These increases do not change your six character stats, it only increases your skill odds.

No STAT skill can be greater than 5/6