Do i need a license for

the reson i ask is it is im working with people to keep them off the streets and out of truble and i dont whant to be in truble i thank any all and any one who can help me in this

It's called LAN game.

Well, you buy the game DVD, install it on many computers, say, three computers. Then one computer hosts a game as a server game, then the others join the game.

What game is this? Do you own a legal version of it?

Agreed. Pirated game brings troubles and difficulties.

Each pc can have the game installed off a single DVD, but each pc must use its own licence.

That's correct, when setting up a LAN event each PC will need it's own KEY (license). If you try using one KEY on 2 PC's or more it simply will not work, the system will detect that the KEY is already in use.

Perhaps we can all stop guessing?

Which game did you have in mind? Each game has their own End User License Agreement (EULA). In other words, with one game you could buy 1 copy and intall it on any PC (older games) or sometimes they give you a number of times the game can be installed (new games). Other EULA found in games consist of using a serial code or login (if it's login in an online server) in which you would have to buy each copy seperately even if it it's LAN gaming.

Nobody is guessing, AFAIK all MP games are tied to a single key. This means that you cannot have 2 PC's running on a single key for the sole purpose of playing "ONLINE" (MP).

I really hate to disagree with a Moderator but until we know which game he/she is asking about, we really can't confirm (or assume) anything about EULA and it's LAN restriction/exemptions. Furthermore, the person is calling on behalf of an orginazation or government service and breaching the EULA as such is far more serious than a breach for personal use (at least, legally) ...so we need to know the specifics to answer this specific question.

That said, most will require each user/player to have their own serial or server authentification to play with other players (LAN or WAN).

blackened_19: Your best bet is to read the EULA for the game in question. If unsure, let us know which game you're enquiring about and we'll try and answer to the best of our knowledge.

Well let me re-phrase, most modern games that have LAN as an option normally are tied to one key per PC. This is simple, find an MP game that will let you use the same key on multiple PC's and I will give you the benefit of the doubt  

It's a simple assumption, which is probably right....but an assumption nonetheless.  

Agreed  

If you do find one let me know, I wouldn't mind setting up a LAN party at my house for cheap  

Technically (and this goes for you two blackened_19), you could get some pretty cheap games on STEAM or retail and make it a LAN party. I'm thinking of the old Blizzard games (Diablo 2, Warcraft 3, Starcraft 1).

i.e. http://www.amazon.com/Diablo-2-mac-PC/dp/B00002CF9M