Recommendations For Multiplayer Only Tactical Shooter With Bots Thread

Standalone ones and mods for low spec PC's and do allow modding and no single player. Counter Strike 1.6, Counter Strike Source and Insurgency Modern Infantry Combat(Because it is perfect for low spec PC's although the game isn't active anymore) are perfect examples. My PC's processor is the Intel i5 and the graphics card is the Intel Integrated Graphics HD 3000. Also, the RAM is 8GB. All suggestions will be appreciated.