# BACTION Command [GstarCAD 2027](Help%20System/GSTARCAD/2027/Index.md) → [Commands](Help%20System/GSTARCAD/2027/Commands/(Commands).md) **Function Description:** This command is used to add actions to dynamic block definitions. This command is available only in the Block Editor. Actions define how the geometry of a dynamic block reference moves or changes when the custom properties of a block reference are manipulated in a drawing. You associate actions with parameters. **Command Access:** > **Icon:** ![](Help%20System/GSTARCAD/2027/assets/6592ceaced20902ea7fde60e63496b8ebbbe91b2b5f782c049fe35a92cb22123.png) > **Menu:** / > **Ribbon:** Block Editor > Action > Action > **Toolbar:** / > **Command:** BACTION > **Alias: /** **Command Prompts:** ``` Select parameter: ``` --- **Related References：** - [Commands about Dynamic Blocks (GstarCAD 2026)](../../2026/Commands/Commands%20about%20Dynamic%20Blocks.md) **Related Tasks：** - [To Specify Settings for Parameters and Actions (GstarCAD 2026)](../../2026/Commands/To%20Specify%20Settings%20for%20Parameters%20and%20Actions.md) - [To Specify the Text Color for Actions (GstarCAD 2026)](../../2026/Commands/To%20Specify%20the%20Text%20Color%20for%20Actions.md) --- [Original help](https://www.gstarcad.net/help/GstarCAD_2027_en-US/detail/commandReferences/BACTION.html) · © Gstarsoft Co., Ltd.