[PF]I can't understand effect of arrows.

[isildur]

For example, rule is clear for tangleshot(only effect) arrow or bleeding(damage, +effect) arrow.

but other, for example Splintercloud, thistle...... whatever, unclear.

[Occasional Sage]

Where are you finding these arrows?

[Platymus Pus]

For example, rule is clear for tangleshot(only effect) arrow or bleeding(damage, +effect) arrow.

but other, for example Splintercloud, thistle...... whatever, unclear.
Hoping this is accurate.
http://www.obsidianportal.com/campaigns/seconddarkness/items/alchemical-arrows

Splintercloud Arrow: The shaft of this arrow is formed of numerous small bone fragments painstakingly glued together. When fired they tear themselves apart, forming a 5-foot burst of razor-sharp bones that deals 1d3 points of piercing damage (Reflex DC 18 negates).
worthless

And this may be the thistle arrows
http://paizo.com/threads/rzs2kvxn?Thistle-Arrows-and-bleed

[Fax Celestis]

They're from Elves of Golarion. AFAIK, they only do their special effects unless otherwise called out.

[Erik Vale]

Splintercloud do 1d3 Damage in a 5ft Burst.
Thistle cause a Bleed Effect for 1d6 rounds, I think it's 1 HP/Round.

[isildur]

Than poison arrow just deals bleed damage?