Infiniti2000 said:
No, the monster's initiative is not rolled until he's aware of combat.
Why? What would that change? The monster doesn't get a combat action until he actually notices the encounter, but there's no reason you can't roll the die early. Your result will be exactly the same.
When setting up big encounters, sometimes I record an initiative roll for each NPC at design time, before the game session even starts. This still gives exactly the same results as rolling each time an NPC hears combat, but it speeds up combat because I don't have to stop and roll initiative as often.
It only makes a difference for new creature entering the combat. I agree you don't need initiative counts unless such a thing happens. But, as Hyp has shown, a new entrant rolls initiative and if you want to make sure you always go before new entrants you could just choose initiative count 500. Thus, the rogue will always surprise new combatants who might have been unaware of the combat.
And this doesn't strike you as a particularly silly example of metagaming? It makes no in-game sense at all, and worse, it gives more speed advantage to the slowest characters.
Consider a low-Dex fighter who ended up with a negative initiative total. Since he goes last in round 1 anyway, he doesn't lose anything if he Delays until the beginning of round 2. Using your rule, he could declare that his new initiative total is ninety million, meaning he would automatically surprise anyone else who shows up. When the world's fastest ninja happens upon the fight with his initiative roll of 40, the hapless slow guy will get the drop on him.
Meanwhile, the other PC is a speedy high-Dex rogue who rolled a 28 init. He should be way faster than his buddy the fighter, yet for some reason he can't react as quickly to the ninja's entry. If he wanted to take advantage of the same rules loophole to go "earlier", he would have to Delay for an entire round, effectively giving up all his actions in round 1.
I don't think this is the intended meaning of that rule.