Alternative Take X (3.5e Variant Rule)

Introduction
In regular games, when a character needs to resolve an obstacle in a nonstandard manner - that is to say using skill checks to circumvent, solve or otherwise decide the manner in favor of beating it to submission with brute force - they often take 10 or take 20. This has proven to be an adequate measure as long as a character has sufficient time available to perform the action, and isn't currently threatened by combat. However, between taking 10 and taking 20, there is a rather huge gap to be exploited. What if you could use just as much force, skill or luck as is needed to succeed, and not more?

Rule Mechanics
The duration of any difficult check you make depends on its DC. While actions at a DC below or equal to your appropriate skill or ability modifier +1 are still trivial and cannot fail, and actions at a DC over your appropriate skill modifier +20 cannot be completed by you under this particular situation, a check whose DC you can overcome by rolling a d20 and applying the appropriate skill modifier requires just as much time as is needed to roll at least the necessary number with a 65% probability, given that you get one check per round. For example, the chance of rolling an 8 or higher on a single d20 roll is 65%, and as such, a skill check that you require natural 8 or less to beat takes 1 round to complete while not under any immediate danger. Alternatively, you simply try until you succeed, spending as many rounds needed for your character to succeed at the given task, provided success is possible.

Examples
Gortok the half orc barbarian tries to break down a strong steel door with a break DC of 26. His Strength is 20, giving him a +5 modifier. Under regular conditions, success is not possible. Frustrated by his failures to break down the door, he enters a barbarian rage, gaining a +4 bonus to his Strength and Constitution that, with his usual Constitution score of 16, will last for 8 rounds. Trying again, Gortok now needs a roll of 19 or higher to succeed on breaking down the door. Unfortunately, he cannot take 19 quickly enough to break the door down before the effects of his rage disappear. As such. Gortok fails to break down the door yet again.

A burglar tries to open a door with his Open Lock skill. His skill modifier is +12. The difficulty of the lock is as of yet unknown, and while wary of any possible watchmen on patrol, he starts carefully picking the lock. On the 5th round, the lock suddenly clicks open; the Open Lock DC was 29.