Defend the Core is a co-op vs bots mode where you defend the core against waves of bots. For some reason the bots are attacking the core. If the core gets destroyed, then there is a chance that both the core (and the mine the core is in) will collapse and explode. However, don't get too close to core! The radiation surrounding the core will still damage you just as it does in Capture the Core.
Since this is a team based mode, this should be a bit more difficult than the standard vs bots mode.
Rules are simple:
Defend the core.
You win after all of the waves of bots have been defeated.
If the core is destroyed, then the bots win (and maybe the mine explodes)'
You earn points by destroying the bots or by repairing the core.
Also, there can be a pure PvP version where one player team attacks and one player team defends