Probably zero, this game looks incredibly bareboned. Seems like they already revealed everything this game has to offer (besides extra maps of course).

Good job Nintendo. We don't need no stinking chat in our online games. We are all little kids who need protection from the bad predators playing these games, not to mention we are also anti-social.

So many strange decisions this company makes, plus this game seems very lacking. Real shame too since it looks fun.

Think of the children!

The more abilities you add, the harder it is to create an AI that acts intelligently or fairly.  You usually end up with bots that spam one tactic or abuses one ability to the point of being really annoying.  The sheer hell of games that give AI grenades, for instance.  Running around and shooting would be easy but I can imagine that the squid abilities are hard to balance.

A map on the pad-thing that shows the position of your allies in real-time would be awesome.  That could make up for the lack of communication.

I wonder if "local multi-player" has to be filled out with internet players?

It does that. You can even touch the gamepad to jump straight to them.

Nintendo's done discrete replacement of dropped players by CPU in many of their games for years, actually. Brawl and Mario Kart Wii featured it, which was continued to Smash 4 and Karts 7 and 8, so likely that will happen here, but neither of those games will populate an incomplete match with CPU players upfront.

In regards to no communication, how do you get around the fact of screaming trolls and the endless stream of profanity that voice chat inevitably becomes? The whole affair just seems unpleasant from whenever i've seen it.

1 - A region based matchmaking would be better. Depending with who you are matching with, there will be a lot of lag. Most games give you the option or simply only match you with players in the other side of the planet if you don't have anyone playing in closer parts of the world.

2 - It wouldn't matter if they didn't screw up with 4.

3 - Seriously? A online multiplayer game with only one mode in 2015? Not even the basic ones like capture the flag or conquest? Are they expecting it to sell? CoD and BF comes with more than 10 modes, even TLOU has 3. It's unaceptable. 4 vs 4 could be bad, but some games resort to it if the gameplay demands. It can be the right choice for a game that has the ink mechanics, since it makes each player do a lot of things in the map (like Transformer games, where 4 vs 4 looks good because the players are giant robots flying, running and shooting all over the place).

4 - Team communication is important in online team based MP games. It's basic since 2006. Even portable games have it. You need to coordinate your team, every clan player on MP competitive games know that he has to play with a headset and act like a team. Seriously, this is dowright embarassing.

I don't see why they wouldn't have voice chat and just add a mute button like most online games.

It's a freaking console shooter, why should we care about strategy and competitiveness? It's fun for local MP, but PC gaming exists for a reason.

That's ... interesting.  Seems like it would break any objective-based gameplay but it doesn't sound like Splatoon will have much of that, anyway.

Really, they're gearing this up to be a game that kids can pick up and play without getting totally slaughtered by organized opponents.  That's just the way it's going to be.  Still, if they could add other modes besides the standard death-match style, they could limit voice communication to only those modes.

Or, possibly, they aren't expecting very many people to keep playing for very long, so they're trying to keep the pool as undiluted as possible.  That might be a sign that this game will come in well below expectations.