Lead Developer, Stardock Entertainment
Published on September 24, 2010 By CariElf In Elemental Dev Journals

It's been awhile since I've written a dev journal and we've got some new faces around here, so I'll take the opportunity to introduce myself. I'm Cari Begle, and I'm Stardock's Senior Game Designer and the programming lead on Elemental.  I've been working here at Stardock for 10 years.  

Today I'm going to talk about Multiplayer.  I'll start with a quick rundown of the features for the people who haven't tried the beta,  and then get into some techie talk for those of you who like to peek under the hood.

Elemental is true client-server where we host the servers, rather than the host player's machine acting as the server (which is a modified version of peer to peer) or true peer to peer where all the clients are connected to each other.  This means that shouldn't need to open ports, and if the host player drops, the server picks a new host and the game can continue.  

There are two multiplayer modes: quick match and custom games.  In quick matches, you choose either 1 v 1 or 1 v AI, pick your sovereign and faction, and you will be matched with another player on a randomly chosen map. In custom games, the host picks the world settings and how many players and then waits in a lobby for other players to join by clicking on the game entry in the available games list.  

With 1.09, we're enabling multiplayer save games for custom and 1 v AI games.  Only the host can save, and the game also auto saves periodically. The save games overwrite, so there is only ever one save per game, and if a host player quits or disconnects before the end of a game and the new host saves the game, the original host's save game is removed so that the new host is the only one with a save for that game.  Save games are also automatically removed when the end game results are posted.  Save games are saved to the cloud, so they can be loaded from any computer as long as you're logged in as the player who saved it.  

In order to help you out at the beginning of a multiplayer game, you start with a spouse.  Also, all the multiplayer maps have gold and fertile land placed around the starting locations of the players.  If you let the game pick the map randomly, it will attempt to pick one that has enough starting location for all the players, but if you open up additional slots you may need to return to the world setup screen to pick a new map.

All battles are instant battles like in Civ5. We won't be enabling tactical battles in multiplayer until after they've been revamped.

To chat, hit the quote/single quote key.  Currently, it only supports chat to all because I need a better dialog for it with tabs or something. 

Multiplayer is interesting to code because you can't simply do something, you have to send a message and wait for the response so that all the clients stay in synch.  This means that you can't code linearly, and you have to handle not receiving a response.  It's much like programming a multi-threaded application, except slightly more complicated because you're sending and receiving data from other computers, not just other threads.  It requires you to think a different way when writing your code, and unfortunately most schools don't really do a good job of teaching this, even the game development schools like Digipen and FullSail.  At least the graduates from game dev schools generally have more practical programming experience than schools with a traditional computer science degrees.   

Say you want to move a unit to a notable location.  If you were only concerned with single player, you'd simply translate the coordinates of the right mouse click to world coordinates, set the destination so that the unit can calculate a path, and boom, it starts moving as soon as the path is calculated.  In multiplayer, there are more concerns.  

To start with, every object in the game that is not purely cosmetic has to have the same ID as the corresponding object on the server and other clients so that it can be identified.  This allows us to send events which can originate either on a client or the server with the data needed to perform the desired action, and an identifier in the event to indicate what the action is.  When the event is received by the server, it processes it and either marks the event as failed or succeeded and in most cases forwards it to the clients to be processed. In some cases, like when the player requests a new turn, we just want to notify the server and not forward the message to the other clients.  Then when all the players have requested a new turn, the server sends out an event notifying the clients.  When the server or clients receive an event, they use the data stored in the event to access the objects that sent the event and perform the action that was requested.

For example, if Unit A attacks Unit B, I create an Attack event and store Unit A's ID as the attacker and Unit B's ID as the defender.  The event is converted to a block of bytes and sent out to the server.  The server restores the event from the block of bytes and gets pointers to Unit A and Unit B.  If unit B isn't already dead from a previous attack, the server performs the attack and stores the results in the event, which it forwards to the clients.  The clients receive the event, get pointers to A and B, and process the battle results (brings up the results screen, levelupwnd, etc). Now, since turns are simultaneous, it's possible that Unit C may have also tried to attack Unit B but was a little slower and so its event arrives on the server second.  If Unit B is already killed, the server simply marks the event as failed and forwards it on to the clients so that they can handle the failure.  Otherwise, the event is processed normally.  

Well, I've stayed up working on this journal later than I intended, so I'm going to call it a night.  

 

 

 

 

 


Comments (Page 2)
on Sep 24, 2010

Since you brought up pain...

 

This 10 second timer thing either needs to be per game adjustable or needs to go all together. If another player simply wants to hit "Next Turn" and I'm trying to stage several events, I'm hosed if I can't make everything happen in 9 seconds.

 

Also, I got locked up in my game where I couldn't end a turn at all. I could click on all sorts of things, but I could NOT progress the turn. 20 minutes later, I just quit. I don't know if somebody clicked "next turn" while somebody was moving or what, but it was pretty frustrating.

Any ideas?

on Sep 24, 2010

[quote who=
Quoting riadsala, reply 10Any plans for supporting PlayByEmail?
No, we will not be supporting PBEM or hotseat as they're not compatible with simultaneous turns.[/quote]

 

that's a real shame, as that's the one type of multi-player I'd be interested in for a game like this.

 

 

on Sep 24, 2010

Simultaneous turns are way too important to sacrifice for something like hotseat, in my opinion. I used to HATE trying to play heroes of might and magic and ragequitting after 20 minutes because 10 of those were spent waiting.

on Sep 24, 2010

That's like getting up and kicking over the chess board because it's taking to long for the opponent to strategize....

I understand some people want a fast game, sometimes I do too, but I'd rather see people given enough time to think out their moves a bit more.

on Sep 24, 2010

Heavenfall
Simultaneous turns are way too important to sacrifice for something like hotseat, in my opinion. I used to HATE trying to play heroes of might and magic and ragequitting after 20 minutes because 10 of those were spent waiting.

Which is the great thing about PBEM, you can go play another game while waiting for them to take their turn.

on Sep 24, 2010

1SuperG
Since you brought up pain...

 This 10 second timer thing either needs to be per game adjustable or needs to go all together. If another player simply wants to hit "Next Turn" and I'm trying to stage several events, I'm hosed if I can't make everything happen in 9 seconds.

Also, I got locked up in my game where I couldn't end a turn at all. I could click on all sorts of things, but I could NOT progress the turn. 20 minutes later, I just quit. I don't know if somebody clicked "next turn" while somebody was moving or what, but it was pretty frustrating.

Any ideas?

We are planning on making the timer adjustable.

I'm trying to track down the turn button won't won't work thing. Usually it can be 'fixed' by putting one of your units on guard or hitting pass.

on Sep 24, 2010

1SuperG
That's like getting up and kicking over the chess board because it's taking to long for the opponent to strategize....

I understand some people want a fast game, sometimes I do too, but I'd rather see people given enough time to think out their moves a bit more.

The two are not mutually exclusive. The turns should be simultaneous, but the time should be generously adjusted so that if you want time to think, you can.

It's not about taking something away from the individual, it's about saving time for everyone. If you've got a multiplayer game with 5 people that each use 10 minutes for their turn, one turn can either take 10 minutes or 50 minutes. There it is, the best reason in the world never to ditch simultaneous turns. How many players does Elemental theoretically max out at? 16?

As far as I am concerned, I wouldn't even call a computer game without simultaneous turns multiplayer. Only one person is playing at a time. That's how terrible I think that "game" mode is.

on Sep 24, 2010

Ok, then we're on the same page. I'm all for everyone being able to plan out at the same time, I just don't want to be tied to another players decision to pass.

on Sep 24, 2010

I haven't tried out the multiplayer yet CariElf. I admire the balance you applied to the game,but once I saw I can't use my Gandalf character I was saddened. Glad I read you balanced out the maps that was one of my concerns. The Battle of getting out MP is over,mastering it for everyone's enjoyment has just begun(from what I read).

One thing I admire about your staff is you guys do these journals almost everyday to tell people whats going on. I don't see that everywhere. And I think if you guys keep this up,pour out updates stay alive from the criticism from "some" harsh forum crowds who always want more;this game Singleplayer and Multiplayer will be a great gaming experience.

I am being a little optimistic,but you guys did a great job in Sins gl hf

on Sep 24, 2010

Turns should have a minimum amount of time before the timer can activate unless everyone has hit end turn.

on Sep 24, 2010

Will custom sovereigns and custom factions be added into multiplayer at some point? The customization features are such an integral part of this game, it's really a shame if they were to be left out of multiplayer!

on Sep 24, 2010

Oh almost forgot: On my system there is a strange problem where the unit walking animations seem to jerk and don't progress smoothly. It's very conspicuous and only happens in multiplayer.

on Sep 24, 2010

   With all due respect...a disgraceful multiplayer implementation or non-implementation. AOW & AOWSM has a great tb/mp "system". Stable to this day. Hell...Alpha Centauri/SMAC worked wonderfully. Hell...HMM3 worked. These are all "old" games. What am I missing? I am not a programmer so I don't know why...I am a purchaser/supporter of good products that work ( as advertised ). Oh well, my mistake for being "fooled".

on Sep 25, 2010

Heavenfall

As far as I am concerned, I wouldn't even call a computer game without simultaneous turns multiplayer. Only one person is playing at a time. That's how terrible I think that "game" mode is.

That "Game mode" is called "Turn Based". You know, like a Turn Based Strategy game?

Simultaneous turn, in my opinion, are a poor attempt to reflect RTS mechanics. The fact that you could retreat your unit before the other person has the time to select it, rather defies the concept of turn based strategy games. I'm not too found of timers either. All those things are incorporated to avoid grief and such, again, a semi reflection of competitive play and random peer matchmaking. All things that don't necessarily jive well with turn-based strategy games.

Taking a more concrete example with Elemental, unless it's a tiny map, you won't want to play a game with a random stranger. No way of knowing, before hand, if that person is available for another session later, etc... (Unless you play 30 hours straight ) So if you are playing with someone you "know" I'd be very surprised that you would need to have in game timer mechanics to avoid people from stalling the game or taking too long. You'll know really quickly if the person's playstyle matches your own.

I'm curious how simultaneous turns will work once the game is playable 2 VS AI. If the AI gets to move at the same time as you, try to move your units faster than an AI

Heavenfall

It's not about taking something away from the individual, it's about saving time for everyone. If you've got a multiplayer game with 5 people that each use 10 minutes for their turn, one turn can either take 10 minutes or 50 minutes. There it is, the best reason in the world never to ditch simultaneous turns. How many players does Elemental theoretically max out at? 16?

Although I understand the factor it can summon to think about, how long would it take for 16 players to do a 5 minute turn each... Well that's what TBS multiplayer IS. Have you ever played table top games like, Axis & Allies and Bells of War (WW2 Strategy)? A player turn can easily vary between 20 minutes to 40 minutes. And can even get worse with time. Crazy example, in Bells of War Russian & US player starts in something like 30 turns. Ok, it's modified depending on how quickly the german player takes Poland and the other countries, but it's can still mean that they couldn't play for maybe even the first game session.

In any case, I'm not against it being available. I just hope it would be an option rather than a hard coded factor.

on Sep 25, 2010

CariElf
No, it's the same method as the SP. All the players move their units at the same time, but to get additional moves the players have to request a new turn.
...
No, we will not be supporting PBEM or hotseat as they're not compatible with simultaneous turns.

Still don't understand. There ISN'T simultaneous turns for player in offline game for now. As far as I can see,  it is "true" turn-based, when I move all my units, then computer do the same. NO computer movements during my turn.

Am I miss something? Maybe my Elemental actually totally different from other builds? 

 

BTW, what sort of "simultaneous" turns we speak for now? I can imagine two of it: in first one you move your units, and your opponent do the same, and results calculated in realtime. It would be poor sort of RTS then. I don't like it.

And the second one is better: you plan your movement for all your units, but it gave no "actual" results on this turn. Then, when all players finished, server calculates all numbers and gives results to players. It is not very reaction-based then, not so fancy, but give you "true" simultaneous TB instead. And allows PBEM too.

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