An Attractor Field is a cluster of world lines that lead to a single converging point.
While each strand may be slightly different, they're ultimately part of the same great structure and yield the same end result.
The Alpha Attractor Field is made up of Worldlines ranging from 0% to 0.999999%. In these Worldlines, Makise Kurisu joins the Future Gadget Lab following her speech on the implausibility of a Time Machine. Further experimentation on the design of the PhoneWave leads to the Time Leap Machine, and the attempt by SERN to take control of the research.
The final convergence of the Alpha Attractor Field is the completion of the SERN Time Machine and the enslavement of humanity in a Dystopia headed by the Committee of 300.
The Beta Attractor Field is made up of World Lines ranging from 1% to 1.99%, with the exception of "The Steins Gate," which is divergence number 1.048596.
In this Attractor Field, Suzuha Amane does not become Hashida Suzu and travels to 1975 or 2000. Thus, Titor's emergence in 1999/2000 is another Suzuha and is recorded in world history in this Attractor Field, unlike in the Alpha Attractor Field in which "he" emerged in 2010.
The final convergent result of the Beta Attractor Field is World War Three, fought over Makise Kurisu's Time Travel thesis.
Important characters that were mentioned as dead as well as the year of their death in the Beta Attractor Field are as follows:
Makise Kurisu - 2010 (lives in the Steins Gate)
Okabe Rintarou - 2025 (or declared that he's dead)
Urushibara Luka - 2036 (unknown in the Steins Gate)
The Steins Gate worldline carries a divergence number of 1.048596. As it is under the influence of both the Alpha and Beta Attractor Fields, it does not reach the final convergent result found in either field. Since this worldline doesn't converge upon the Committee of 300 and SERN's dystopia, nor World War Three, there was no need for Suzuha Amane to travel back to 2010 on this worldline.
This worldline is where the true ending of the main plot occurs, and it is dubbed as "Steins Gate" by Okabe. The main draw of this worldline is its unknown future—World War Three over the time travel thesis and SERN's dystopia are averted on it, and both Mayuri Shiina and Kurisu Makise live past August 2010 on it.
As is demonstrated by the rest of the Science Adventure series, the Committee of 300 is still apt to carry out various other schemes in an attempt to take control of the world on this worldline.
The Gamma Attractor Field is made up of World Lines ranging from 2% to 2.99%.
The final convergent result of the Gamma Attractor Field is the completion of the SERN Time Machine and the enslavement of humanity in Dystopia headed by the Committee of 300; however, this time Okabe is working with SERN, and becomes a high-ranking member of the Committee of 300, ruling Japan as the dictator "Hououin Kyouma."
It's important to note that another important event, the "Y2K" crash, did happen in this world line, sparked by a SERN researcher after he discovered one of Okabe's D-Mails.
The Gamma Attractor field is Drama CD-exclusive, and as such only one world line is shown:
Important characters that were mentioned as dead as well as the year of their death in the Gamma Attractor Field are as follows:
Mayuri Shiina - 2010
Hashida Itaru - Unknown
Makise Kurisu - Unknown
The Delta Attractor Field is made up of Worldlines ranging from 3% to 3.999999%. This worldline is noted for it's seeming peacefulness, with neither the threat of SERN nor Nuclear War as a looming threat.
While the PhoneWave does exist, and is used at least a few times, it is not central to the Future Gadget Lab's work, and instead takes a backseat while they focus on other projects, such as "Darling, You Idiot!" and a dream reading device. Notably, SERN's influence is incredibly weak at the far end of the attractor field, however as the deviation on the Divergence Meter goes lower, their presence seems to grow stronger.
It is also notable that both Makise Kurisu and Shiina Mayuri are safe on this worldline, without the central dilemma of Alpha and Beta., and Kiryu Moeka is more committed to her work as a reporter than in either Alpha or Beta, where it was primarily an excuse.
It is a negative divergence world line, hence the lack of a starting number.
Nothing is known about the future of this attractor field. It is vastly different from others in that Okabe does not have the Future Gadget Lab; he participates in "Rai-Net Access Battlers" tournaments and the only person that he's friends with is Faris. What is certain is that SERN won't complete its time machine in the Omega field, because the lab isn't together to create the Phone Microwave and subsequently the Time Leap Machine.
However, that doesn't imply that the future of Omega is a safe one. The very presence of the Divergence Meter is ominous; it seems that time travel and the existence of world lines will emerge in this Attractor Field, or else the Divergence Meter would cease to exist.
Almost nothing is known about this world line. After the "Irreversible Reboot" ending, Okabe and Suzuha travel to 1975 together. No divergence value is known.