Lag: How does it work?

Generally speaking, the higher the ping, the less fine control a player has over their movements. Most games attempt to compensate for ping; this can result in a more playable experience for the lagger, though of course it may cause other players to miss them or them to miss players.

Ideally, a player with low ping, say, <33 has an advantage over higher ping players, as they're able to react in a much shorter time. That said, a player who is lagging might avoid a hit or land a hit they wouldn't if they were not lagging.

I'm not terribly familiar with the mechanics of game networking besides what the average player knows, though; so take it with a grain of salt. Most servers have a maximum ping amount to avoid slowing down the server's response times.

 

There's no general solution in any game when it comes to lag compensation of any kind.

There's 3 major forms of lag:

• Local/Framerate/CPU/GPU lag - basically something in the local machine cant keep up with what the game is throwing at it, so the player sees a drop in framerate. There are different ways of dealing with this; the game may make "bigger steps", or it might "slow down", or it might skip rendering frames, or all manner of things. The only way to improve this is to throw more hardware at it, or optimise the game (which can only be done so much practically at this point).
  
• Network Bandwidth/Packet Loss Lag - the player's network cant keep up with the amount of incoming data - unless it is a temporary burst from something like 1000 bombs being spawned (they'll be gone soon), they'll never catch up and eventually disconnect. This is more commonly caused by something else (eg youtube) saturating the network and taking bandwidth away from the game. Packet loss (bad connection) can make this worse (as packets have to be re-sent, taking more of the precious bandwidth).
  
• Network Ping Lag - the player is situated a long way from the server and it takes a long time for communication to get back and forward. Generally <100ms is ok/good ping, >300 is borderline unplayable ping. This will cause a flat delay between the player doing something and it showing up on the server (and then depending on the other player's ping, showing up on their machines), and is the general reason that playing over the internet can never be perfect. This can cause things like players being "on the wrong side" of each other on each machine, which causes both of them to "push/pull" the other one - or, if all of the state is kept on the server, causes that annoying "rubber banding" when you go around a corner too tightly or collide with another player.

As to the "ethics" of joining with ping; sometimes you have no choice. If there's a game closer to you with players, you should in general prefer it - for everyone's sake! If not, imo it's fine to play with some lag. The people complaining about your lag don't know the half of it, it sucks much more to be lagging than to be playing with someone laggy.

Hope this helped :)

 

In the case above, this is the server experiencing the "CPU lag" rather than some new kind of lag, but you're right that it shows up as very strange things for the client.