for example you can do something like a clock that gives everyone a score of "spawn" 20 times /s if they have it 0 or more, then they get tp'd to the real spawn and that gets set to -1, also gamemode, if the "real" gamemode is meant to be 0, you can make the world/server gamemode 2 and then tp every1 with gm 2 to the real spawn and set their gm to 0 at the spawn area (reliable). Then maybe if your world is custom made, you could make it so that if someone is outside of dx,dy,dz box, they get tpd to the spawn, this also fixes people escaping the map.