Putting out here that the ASB Handbook thread has an "
Effects Timing" section that seems pretty complete, following in-catridge precedence. Except, of course, for the fact that switch phases mess up said in-catridge precedence. So looking at it, I'd propose some slight modifications (propositions are in bold underlines):
Proposed Start of Round said:
The following effects occur before the first action of the round is even touched:
- Trainer replaces KO'ed and/or self-switched active Pokemon where applicable, in that order.
- Healing Wish and Lunar Dance restore HP.
- Entry hazards like Stealth Rock take effect in the order they were set up.
- Trigger abilities that automatically activate when the Pokemon enters play activate.
- Toggle abilities toggle. If Zen Mode is toggled to the default effect while Darmanitan has less than 50% of its HP left, Darmanitan reverts to its normal form.
- Switch/Counterswitch phase is initiated, and return to Step 3 where applicable.
Proposed End of Round said:
The following effects occur after the last action of the round:
- Phazed Pokemon is sent in.
- Weather duration (other than Fog) is lowered by 1.
- Status effect removal due to Shed Skin, Hydration and Healer occurs.
- Perish Song counter decreases by 1 and any Pokemon with a Perish Song counter of 0 are knocked out.
- All ongoing effects with a duration given in rounds that are not specified elsewhere have their remaining duration lowered by 1.
- Paralysis stage on all Pokemon drops to the next lowest level, and paralysis is cured on all Pokemon whose paralysis stage drops to 0%.
- Stat boosts and drops that are due to decay do so.
- Speed Boost, Harvest and Moody activate.
- Toxic Orb and Flame Orb activate.
Take a scenario where Trainer Hugh switches in Pokemon A after a KO on Hugh's team. Pokemon A would actually be visible, and thus would trigger all sorts of effects (Healing Wish, entry hazards, Intimidate, etc. etc.)
before Hugh decides to double-switch by initiating a Switch phase.
Gameplay-wise, this opens up tactics such as double-switch Intimidate and multiple entry hazard damages. This way, initiating a Switch phase counts as a round in itself, even if all you do is switch into a self-KO, paying a price to gain an edge in the battle. Gerard's question can also be answered - the flow will skip from "Start of Round" straight to "End of Round", since no action were really taken.
EDIT: After going through that section, I'm surprised to find no mention of Toxic counter. That's probably a separate issue that could be hotfixed, though.
* * * *
As to the first question in Dogfish's OP, I'd say no. It will only drag on the match, and furthermore I believe it is an unnecessary nerf to Illusion. Under normal circumstances, Illusion breaks in the round the Illusion mon recieves damage, but if referees were to post stats as soon as Switch phases are concluded, a smart player could realise the ruse right away, thus adjusting accordingly and null any advantages Illusion could provide altogether.
To address Red's issue about an Illusion mon being phazed in, I think the issue can be solved by
setting a default Illusion teammate when the Trainer PMs the referee the team before the match, just as ASB players used to equip before the match starts by sending the details to the referee beforehand. I agree that this would raise another problem (especially concerning "Bring 6 Play 4" and similar formats), so there might be a better solution.