---
title: "Packet 40: BlockLine"
description: "The retail 1.x client's normal multi-block placement request. The server rasterizes and validates the line between both voxel endpoints."
canonical: "https://aosplay.net/protocol-168/packets/40"
markdown: "https://aosplay.net/docs/protocol-168/packets/40.md"
last_updated: "2026-07-16"
protocol: "Ace of Spades Battle Builder 168"
packet_id_decimal: "40"
packet_id_hex: "0x28"
direction: "C→S"
family: "Building"
implementation_status: "Handled"
evidence: "Live-verified"
wire_size: "18 bytes"
---

# Packet 40: BlockLine

> The retail 1.x client's normal multi-block placement request. The server rasterizes and validates the line between both voxel endpoints.

- **Decimal ID:** 40
- **Hex ID:** 0x28
- **Direction:** C→S
- **Family:** Building
- **Status:** Handled
- **Evidence:** Live-verified
- **Wire size:** 18 bytes

## Exact wire layout

The application packet ID is the first byte. The remaining rows are in decode order. Byte sizes exclude ENet headers, wrapper prefixes, LZF chunk framing, and compression effects.

| # | Field | Encoding | Bytes | Purpose | Condition |
| ---: | --- | --- | ---: | --- | --- |
| 0 | `packet_id` | u8 | 1 | Always 40 (0x28). | — |
| 1 | `loop_count` | i32 LE | 4 | Simulation-loop stamp used for ordering, prediction, or reconciliation. | — |
| 2 | `player_id` | u8 | 1 | Compact player-slot identifier. | — |
| 3 | `x1` | i16 LE | 2 | x1 value. | — |
| 4 | `y1` | i16 LE | 2 | y1 value. | — |
| 5 | `z1` | i16 LE | 2 | z1 value. | — |
| 6 | `x2` | i16 LE | 2 | x2 value. | — |
| 7 | `y2` | i16 LE | 2 | y2 value. | — |
| 8 | `z2` | i16 LE | 2 | z2 value. | — |

## Encoding conventions

- `LE` means least-significant byte first.
- `fixed16` is two-byte sign-magnitude at 1/64 precision.
- `orientation16` uses the measured 1/8192 orientation mapping.
- NUL strings consume their encoded byte length plus one `00` terminator.
- Counted arrays repeat immediately in the documented order.

## Related resources

- [HTML packet page](https://aosplay.net/protocol-168/packets/40)
- [Complete packet catalog](https://aosplay.net/protocol-168/packets)
- [Packet catalog in Markdown](https://aosplay.net/docs/protocol-168/packets.md)
- [Protocol 168 guide](https://aosplay.net/protocol-168)