http://www.planetquake.com/digitalpaint/v2/docs/ents.html#gamemodePut gamemode 8 on all of your entities (including the worldspawn). Put one set of spawns in the base and one outside (these alternate every round). Put a regular old flag entity in the base (with no teamnumber). Put base entities outside of the base -- if defense touches them, they die. Offense has to grab the flag and touch them to score points.
