Solo Assassin help *possible spoilers*

[NDIrishFan7]

hey, i started a halfing assassin soloing (neutral evil), im level 17 and ive one the following quests:

Circus
Slaves/Copper Coronet
Unseeing eye/killed Kich with Kangaax arms n legs/the dead temple quest
Mae'Var/Shadow Theif guild hall

im going to do either trademeet or De'Arine now, or maybe the tanner quest

i have a prof in:
short sword
Katana
short bow
single weapon style

im using:
Tuigan
Celestial
ghoul hide

i also have a few mods, so i use teh staff of elemental mastery for help

only thing is, i cant seem to hit crap. lots of times my backstab doesnt multiply teh damage (i know bows cant, but even Celestial wont do teh damage multiplyer) and when fighting 1 v 1, i can thit crap. my base thac0 is 10 i believe. any ideas? i summon the elementals alot, but they get 90% of the kills now. please help! n ive played this countless times now, so dotn be afraid of being vague

[Berethor]

Its not anything new to me, I beat the game my first time with an assassin.

for backstab, get the sword from renal, short sword of backstabbing, get boots of speed, maybe shadow armor or nights gift, and then you will have a better chance.

You will be better at hiding and staying quiet and you will be fast.

you will get behind them and even if you miss the first time, you should still have 2 more attacks before you become visible.

montiollos cloak is also useful but you cant complete it until throne of bhall, and you cant use it without the HLA, use any item.

[Deadalready]

First of all, DUMP the Celestrial Fury as wonderful a weapon it is, it is by all means a fighter weapon. In the hands of a thief, unless you plan on bashing it out on the head of your enemies, Celest is nearly completely useless.

When compared to better suited weapons like the Short Sword of Backstabbing, Pixie Prick or Daystar there are by far better options, that almost guarantee better damage.

Since you already have a proficiency stat in short swords go with the Short Sword of Backstabbing, upgrading to the Short Sword +4 later on, if considering a change I highly recommend going with Staves and using the staff of Rhynn and the Staff of Striking for excellent damage. With Throne of Bhaal installed you could even get the Staff of Ram.

I can't remember exactly what armour I used earlier in my games but try using Mae'var's shadow armour or the Armour of Deep Night.