Example 5 players

#include "ScriptPCH.h"

std::vector<Player*> Players;
bool BgRunning = false;

class TEST : public CreatureScript
{
public:
    TEST() : CreatureScript("TEST") {}

    bool OnGossipHello(Player* player, Creature* creature)
    {
        // blah blah
    }

    bool OnGossipSelect(Player* player, Creature* creature, uint32 sender, uint32 uiAction)
    {
        switch(uiAction)
        {
        case GOSSIP_ACTION_INFO_DEF+1:
            {
                if(BgRunning)
                {
                    player->GetSession()->SendNotification("BG is already running");
                    return true;
                }
                Players.push_back(player); // add player to the list
                if (Players.size() >= 5)
                {
                    for (auto it = Players.begin() ; it < Players.end(); it++ )
                    {
                        if(!(*it)->IsInWorld())
                            Players.erase(it);
                    }
                    if (Players.size() >= 5)
                        for (auto it = Players.begin() ; it < Players.end(); it++ )
                        {
                            (*it)->TeleportTo(0, 0.0, 0.0, 0.0, 0.0);
                            BgRunning = true;
                        }
                }
            }
        }
        return true;
    }
};