Timeline

If time is a river, then every action is like throwing a rock into the flow. Most merely cause some splashing; momentary (pun intended) splits that instantly rejoin. If time is a bundle of yarn, knotted and webbed, then most decisions merely fuzz the fibers. But some actions cause divergence. The stream cannot trivially rejoin around the rock, part of it diverted over a cliff (ok, the metaphor is getting out of hand).

Critical Points

Some decisions occur at critical points, where any change is fraught with consequences. These critical points cause splits in the timeline that last more than momentarily. An example of such a critical point was the instability encountered by the Phoenix Empire upon the occasion of the first regeneration of the Eternal Emperor. It was touch and go--in one timeline, he survived and was reborn with increased strength but with a need to consolidate, leading to the empire's withdrawal from the Great Rift. In another, he died, and with him the empire.

Note that timelines, once split, can rejoin later. But that requires another substantial event in one or both timelines.

Locality

Timelines are not universal. The effects of decisions tend not to have huge scope--a "froth" decision might only reach as far as one person's life; no splitting occurs for anyone else, not even for an instant. A significant point may cause divergence across a continental scope (such as the above-mentioned elven empire decision).

Fixed Points

Unlike a critical point, where differences in behavior lead to splits, a fixed point is an event that occurs across a bundle of timelines. The exact details may vary but the core similarity remains. One such event was the Cataclysm itself; another the ascension of the Archon of Time. The Reweaving is another fixed point for the timelines in and around Ikela.

List of Timelines with critical points

Timeline Nickname	Area Affected	Critical Point	Decision	Description
Prime	Everywhere	N/A	N/A	This is the timeline that all the adventures follow/create by default
Fantasy Communism	Sea of Grass	Which party was assigned to Yuuras Zaali	Regime Change	In this timeline, the catalyst-equivalents came back and overthrew the Council Lands government, instituting fantasy communism instead
Frost and Fire	Sea of Grass	Which party was assigned to Yuuras Zaali	Fire, Stone, and Cold	In this timeline, the Catalysts were elsewhere and the listed party handled the Four Towers. Rejoined Prime soon after.
Elven Kingdoms	Great Rift	Did the Phoenix Empire fall?	Yes	Gwerin stayed in the great rift, resulting in mixed kingdoms. The home timeline of Tor Ysa.
Diabolical Doom	Ikela	Was Kozhun's mate killed by devil-inspired assassins?	No	Kozhun as peaceful ruler, Greenwood Reach invaded by devils ~100 AC.