Some people favor waiting till the seer has some important intelligence (e.g. found a wolf, or checked as village someone who's about to be lynched), since that way he has more opportunity to collect intel before he gets targeted for a kill. Others favor just claiming anyway on the second or third day, because otherwise for all people know, the seer already died and that's why they're not claiming.
I'm only going to consider standard setups usually found in
wlf prefixed games for this answer, as larger and more complicated setups will vary on a case by case basis.
I feel one mistake that is often made by people is not valuing a village check highly enough. If you have 3 living village checks, this is often enough intel to win the game by systematically lynching into the pool of unverified players (and there may be other uncontested claims or information about this pool of players).
Another thing to consider is that the village wins werewolv.es by lynching. The numbers advantage that the village has over the wolves means a mislynch isn't always the end of the world. If you think of mislynches as a resource at the village's disposal getting rid of a wolf effectively buys the village an extra mislynch, as shown below.
| Wolves | Villagers | Maximum Mis-lynches | | 1 | 2 | 0 (lose immediately) | | 1 | 3 | 0 (lose by NK) | | 1 | 4 | 1 | | 1 | 5 | 1 | | 1 | 6 | 2 | | 1 | 7 | 2 | | 1 | 8 | 3 | | 1 | 9 | 3 | | Wolves | Villagers | Maximum Mis-lynches | | 2 | 3 | 0 (lose immediately) | | 2 | 4 | 0 (lose by NK) | | 2 | 5 | 1 | | 2 | 6 | 1 | | 2 | 7 | 1 | | 2 | 8 | 2 | | 2 | 9 | 2 | * The normal ratio for wolf:village is 1:3 (1 wolf in 4 players). The tables assume the wolves manage to get a kill every night.
If you know a protector/huntsman is in the game, claiming earlier means it's more likely that role is still alive, and a successful protect also buys the village another mislynch.
If you die without revealing, the wolves might think realise you have dead and fake a seer claim, and that's often enough to win the game for them.
- I am always claiming if the village cannot afford a mislynch.
- I am always claiming if I have 3 living village checks.
- I am always claiming if I have >= 50% of the wolves found.
- I am considering my claim by D4/5 anyway even if I have little info to prevent a wolf getting away with a false claim
This is a similar question to When should the gravedigger claim?
The same applies here as applies there:
There is no hard and fast rule for claiming. You need to consider what is best for the village before revealing any information. If there are already roles revealed and the lynch looks like it's going in a good direction why would you claim? Take your time and assess whether claiming helps the village or hinders it. I think this goes for any village role.
Always consider if you're giving helpful information to your team. If you reveal are you just making yourself a target for no reason?