What a new character joins a combat that has already started?
(regarding Scion/Exalted 2e)
That rule is a bit odd. At the beginning of combat, the guy who rolls the most successes wins, and goes on tick 0. Everybody else goes a number of ticks later, based on how many fewer successes they rolled than the winner. The most you can win by is 6, however, which is itself a somewhat wonky rule- if three combatants roll 20, 10, and 0 successes to join battle, the first guy will go on 0, the other two go on 6. I would have made the rule that they go on 0, 6, and 12, maybe.
You note down the number of successes the winner rolled, this is the "reaction count".
Later, if someone wants to jump in, they roll "Join Battle" (their initiative pool), and compare that to the reaction count.
Say the reaction count was 5. If, on tick 20, I decide to join battle, and roll 3 successes, I go on 20 + (5-3) = tick 22. So it's somewhat slower to join battle if the initial initiative winner was fast, even if he's no longer in the battle (got killed, left, whatever). I would probably have said that you're rolling against a 6 whenever you join battle late.
That's a minor quirk, really.
The major problem in the system is that it's possible, in the rules, to get your attacks down to speed 1 reliably. Due to the way actions and resource management happens in the games, being able to take 5 or 6 times as many actions as your opponent is not just a big advantage, it's an overwhelming advantage, AND you take up the bulk of the time at the table with your plethora of actions, leaving the other players twiddling their thumbs.
It's comparable to D&D 3.0 haste- effectiveness in the system is measured in actions taken, and it's such an advantage that it kind of wrecks the timing system as everyone races for speed. A common house rule as a result is that attacks can't drop below 2 ticks.