I did some reading on Latency and it's effect on spell casts. (http://elitistjerks.com/f31/t33457-simulationcraft_model_development/p9/#post1309223)
There is a built-in spell queue in WoW, that queues a spell right after the one you are currently casting under certain circumstances:
- You can't queue a spell during the first second of the GCD. This gives you a Not Ready message.
- You can't queue a spell while your previous spell has more than about 0.3s left to complete. This gives you an "Another action is in progress" message.
- You can queue a spell during the GCD as long as you satisfy both (1) and (2) above.
For a queued spell latency is close to nonexistent. Simcraft models this latency with a standard deviation of 25% centered around 0.075 s. An instant is modeled with 0.150 s and a channeled spell with 0.250 s as default value.
Then I did some testing, but since I don't have an owl I could not get my Lightning Bolt cast time below 1s. However testing showed a few facts, that are implied by the above, but still worth mentioning:
- You can queue instants after spells with cast time.
- I was not able to queue a spell after an instant.
- I was not able to queue a spell after a channeled spell. Instead the new spells cast begins as soon as the server receives the message.
I would be happy to see some input on this. Perhaps someone of you is already modeling lag in a similar way.