Making your own luck

[Heliomance]

Aside from luck feats letting you treat a natural 1 as a natural 20, are there any ways of increasing your chances of rolling a natural 20? Things that let you, say, treat the result on the die as one higher, or something?

[Alleine]

There's a 5th level cleric spell in Complete Champion called Surge of Fortune. It gives you some nice benefits for 1rd/level, but you can discharge it at any time to treat your next roll as a natural 20.

[Runestar]

There are feats which let you take 10 on your checks, effectively removing luck from the equation.

[Heliomance]

That's not what I want though. I want a way to increase the odds of a natural 20, for effects that trigger off natural 20s.

[InaVegt]

There's also a variety of reroll effects, which are not even close to perfect, but which do increase odds.

[Amphetryon]

A Halfling Wu Jen/Mythic Exemplar/Luckstealer/Fortune's Friend build would just about corner the market on methods of creating rerolls.

[Tengu_temp]

Fixed dice.

Special rolling techniques.

Bribe the DM with pizza.

[kestrel404]

There's a 5th level vestige that lets you re-roll any d20 roll once every 5 combat rounds (4, with 2 feats). Between that and the luck feat, that gives you a 20% chance (roughly).

There are a number of other re-roll options as well (cleric's Luck and Fate domains, various luck feats, etc.), but these are all per-day abilities and thus not nearly as helpful.

[grimbold]

There are feats which let you take 10 on your checks, effectively removing luck from the equation.

cant you take 10 on all checks?

and what are these feats that let you take a nat 1 as a nat 20?

[Lapak]

Aside from luck feats letting you treat a natural 1 as a natural 20, are there any ways of increasing your chances of rolling a natural 20? Things that let you, say, treat the result on the die as one higher, or something?

I know you're [EDIT: not] looking for re-rolls, but the easiest way to accomplish this is by rolling more dice. If you're looking for natural twenties on attacks, for example, you might consider grabbing Flurry of Blows or Snap Kick or going TWF.

If it's not attacks, what situations are you trying to trigger these effects?

[Raging Gene Ray]

In Tome of Battle, there's a 1st level Shadow Hand maneuver that lets you roll two d20s and use the higher one. If both hit, you deal 1d6 bonus damage. If not, well, you still got to roll two dice.

[Tokuhara]

I personally love this combo: Pride Domain (on a natural 1, reroll), Luck Domain (reroll 1/day), Third Time's the Charm (see Luck Domain) and anything that lets you reroll.

Played a halfling cleric who worshiped the ideals of Pride and Luck, who was actually capable of rolling 4 natural 1s in a row on a climb check.

my DM actually banned Luck and Pride as player domains because of me ;)