Critical chance can not be less than 5% nor more than 95%.
The base chance for bows is 5%.
There is a full list of general critical strike passives on the wiki.
- 3 x Increased Critical Strike Chance (20%)
- 15 x Increased Critical Strike Chance (15%)
- 1 x Assassination (40% Increased Critical Strike Chance, 20% Increased Critical Strike Multiplier)
- 2 x Bloodthirst (45% Increased Critical Strike Chance)
- 1 x Mental Acuity (30% Increased Critical Strike Chance, 20 Intelligence)
This gives a combined total of +400%
There is another list of Bow specific passives giving a further +120%
Out of the different mods, the "of Incision" suffix gives the most at +38%. This can't appear on all items. however if it could then it would give 304% (only counting 8 times because of the gloves below).
The unique gloves Maligaro's Virtuosity can be used with a bow and gives +50%
There is the support gem Increased Critical Strikes which gives about +105% at level 20.
Some skills give a critical strike chance bonus. For example Elemental Hit gives a +4% for every quality%. (so +80% at max quality)
There is the curse Critical Weakness which gives +10%. However this is treated differently and added after everything else.
Total Possible Crit Chance with a bow is 5% * (100% + 400% + 120% + (8*38%) + 50% + 105% + 80%) + 10% = ~73%
Or an increase of just short of 1,500%. Not that this is practical, but it covers the different ways to boost crit chance.