Here's a post from the Infogrames forum which discusses how to add bots in Unreal 2 sp.
- This is totally unsupported but there is somewhat functional botmatch support in the game if you want to experiment with it (standalone games only -- multiplayer games won't work).
First, you'll probably want to make a new map or change an existing map to contain additional playerstarts and pickups (weapons and ammo).
To start the botmatch use: unreal2 xxx?game=u2.u2deathmatch (where xxx is the name of the level that you want to use.)
Use addbots [x] to add bots to the level.
There are also a number of "mutators" available: unreal2 xxx?game=u2.u2deathmatch?mutator=u2.rocketarena
There were mutators for most of the weapon types last time I looked and there is a "NIU2" mutator which cycles the weapons or gives everyone specific weapons (pretty similar to the NIU mod that I did for UT a couple years ago).
There's no UI for this but you can use: 'setskill x' to set the bots' skill, and 'togglescoreboard' to get a "scoreboard" that shows you the current standings.
Disclaimer: this code hasn't been worked on in over a year and your mileage may vary. I'm pretty sure there was a problem with bots not always respawning when they die, so you may need to useaddbots again from time to time to "replenish" the bots.