Look at this bit:
elseif (%id == (!dmarena) || (
First off your checking if the player id is (!dmarena, if should be $2 == !dmarena
Secondly why have you put || ( at then end? || = or and the bracket should be a curly brace like { not a bracket.
Fixed line would be:
elseif ($2 == !dmarena) {
Also make sure !dmarena is in your cmdlist for the cmdcheck
Oh and one more thing...
vcmp.msg %id vcmp.msg %id Taking you to the Death Match arena...
notice what your doing here? it wont stop it working but i think its best to be pointed out. you've done vcmp.msg %id twice, you only need it once
This should work aslong as theres nothing broken above these lines. Remember to check mircs status window for any major errors