How hard a skill check is hard?

[notdefix]

Hi,

Are there any guidelines as to what skill check bonuses/penalties make a skill check easy/medium/hard for certain skill level?

In my specific case, I have a jammed door that needs to be somewhat difficult to open (using a crow bar).

do_check(source_obj, STAT_st, MODIFIER)

I've tried with various modifier values, but trying hardly equals probability calculations.

 

[Darek]

Don't you normally use "do_check" with "is_success"? Something like this:

if (is_success(do_check(dude_obj,STAT_st,0))) then

As far as I know the game don't use any of this type of check on the strength stat, but do on some of the others.
The modifier is usually "0" but I've seen it be "STAT_ag,-3".
I haven't looked into this but would assume if the modifier is -3, and your your strength is 5, then as far as the check goes your stat is 2 (which means if the game rolls a 1 or a 2 you pass, otherwise you fail).
In other words, every stat point you have over 3 increases your chance to succeed by 10%, for a maximum of 70%

Normally in the game they use a hard check like this on from the stuck doors in Vault City Vault:

if( dude_strength > 6 ) then