Alliances in "Free for all" game type are quite annoying and actually spoil the pleasure of the game. I mean when two players do not take each other pieces, help each other to promote and checkmate and even do not compete after they defeat two other players (one of the allies simply resign immediately). There is "Teams" game type for this!!!
4 Player Chess

Often the winning player cheats letting the other one in the finale to make points to make him seccond. When I was out the green player only had 6 points then got 14 more points just to be seccond. It's not fair when someone passive all the way in the game gets gift points just lke that. Here is a picture attached. I propose that system automaticaly finishes the game when one has 20 or more points then the oponent, in the finale. Thank you very much. Very often we see very good players who worked hard to get points then someone who didn't do anything just slept will become seccond thx to the gift points.

@martonflorian, an automatic claim win has been suggested before and it has some mixed opinions whether players want it or not.

Cheaters on free for all game http://imgbox.com/AS32XraX

It's not that uncommon with uneven pairings. One recent example:
How can I change pieces style? I can't find the option anywhere

A planned feature is a colorblind setting which replaces red and green with white and black. Main reason for this is to make it easier for colorblind people to distinguish the pieces. No other new piece styles are planned as far as I know.

Was is the right word, I'm not active in 4-player free for all anymore. Mostly playing teams where I am nowhere near the top with just 1800 rating.
More importantly though, I am an admin of the 4-player chess club, so I know what I am talking about.

Does someone know when will they add the play-with-friends feature? I have been waiting for that for some time.
I love free-for-all 4-player-chess but I hate it when some players team up and makes double check.
for avoiding this happen when a king is in checked if another player check to this king, the second piece that make double check must die immediately.

I tried to explain years ago that FFA in a turn based game with checks will never really work properly.
It needs to be team based so you keep the turn based cycle:
Team A
Team B
Team A
Team B
etc
You can have 2 players (2 colours each) or 4 players (1 colour each) but it is always 2 teams.
Team cheating in FFA games should be disincentivized by having only the winner gain rating points. All others lose. I would welcome this change. I know variants have been created and perhaps this is one of them. Doesn't solve all the problems but it's a step in the right direction.
How to protect from check mate when 2 players (left and right) attacking by their queens simultaneously? Are they pre-set team or this kind of play is common?
It depends on what variant of 4 player chess game you are playing. In free for all it is considered cheating when there is blatant collusion from the start (like when on national television in 2016 Trump requested Russia's assistance in finding Hillary's emails, and they delivered via Wikileaks). There is no defense to this, just lose the game and try to find others who play ethically. Alternatively you could be playing a Team four player game in which collusion is normal and expected, because each player is explicitly on one of two teams. Hope this makes sense.

I've been thinking lately, that the zombie king when a player retires is unfair. Because, let's say I've been investing my material on attacking an opponent, and he retires, I'm down material against two other players, who has more material and can also mate the leaver, and me of corse. So the points of the one who leaves should be given to the player who took more material to that opponent.
I guess the claim win option is there to get more action. You can't stay too passive, watch the other players kill each other, and then rule the end game against your last opponent. If you fall to much behind on points, your are not the best player, according to the current set of rules. If you are extremely passive, you might even be the last man standing, though still end up in 4th place. More action is more fun, I think.