Excel VBA Advanced: Keyboard & Timer Events for Games

Why Keyboard & Timer Events Matter in Excel Games

Every playable Excel game relies on two pillars: responding to player input (keyboard events) and moving the game world forward automatically (timer events). Without them, a "game" is just a static spreadsheet. This tutorial shows you exactly how to wire both systems together so your Excel game feels alive.

Part 1: Capturing Keyboard Input with Application.OnKey

Application.OnKey binds any key combination to a VBA macro. Place binding calls in a Sub that you run when the game starts, and unbind them when the game ends.

Binding Keys

Sub BindControls()
    Application.OnKey "{LEFT}",  "MoveLeft"
    Application.OnKey "{RIGHT}", "MoveRight"
    Application.OnKey "{UP}",    "MoveUp"
    Application.OnKey "{DOWN}",  "MoveDown"
    Application.OnKey "{SPACE}", "FireBullet"
End Sub

Unbinding Keys (Always Do This!)

Forgetting to unbind keys after a game ends means arrow keys stop working in all Excel workbooks until you restart. Always clean up:

Sub UnbindControls()
    Application.OnKey "{LEFT}"
    Application.OnKey "{RIGHT}"
    Application.OnKey "{UP}"
    Application.OnKey "{DOWN}"
    Application.OnKey "{SPACE}"
End Sub

Key Syntax Quick Reference:

{LEFT} / {RIGHT} / {UP} / {DOWN} — Arrow keys
{SPACE} — Space bar
^z — Ctrl+Z
+{F5} — Shift+F5

Part 2: Running a Game Timer with Application.OnTime

Application.OnTime schedules a macro to run at a specific clock time. By scheduling the macro to reschedule itself at the end of each run, you create a continuous game loop.

Dim NextTick As Date
Dim GameRunning As Boolean

Sub StartTimer()
    GameRunning = True
    NextTick = Now + TimeValue("00:00:01") ' 1-second interval
    Application.OnTime NextTick, "GameLoop"
End Sub

Sub StopTimer()
    On Error Resume Next
    Application.OnTime NextTick, "GameLoop", , False
    GameRunning = False
End Sub

Choosing the Right Interval:

1 second — Slow puzzle games (Tetris at low level)
0.5 second — Medium-paced action
0.1 second — Fast arcade (use Now + 0.1/86400 as a decimal fraction)

Part 3: The Complete Game Loop Pattern

Combine keyboard binding, the timer, and game logic into a clean start/stop pattern:

' ——— Module-level variables ———
Dim NextTick As Date
Dim GameRunning As Boolean
Dim PlayerRow As Integer
Dim PlayerCol As Integer

' ——— Start the game ———
Sub StartGame()
    PlayerRow = 10 : PlayerCol = 5
    GameRunning = True
    BindControls
    DrawPlayer
    StartTimer
End Sub

' ——— Stop the game ———
Sub EndGame()
    StopTimer
    UnbindControls
    MsgBox "Game Over!"
End Sub

' ——— Core loop (called every tick) ———
Sub GameLoop()
    If Not GameRunning Then Exit Sub
    UpdateEnemies   ' Move enemies
    CheckCollisions ' Test for hits
    RefreshDisplay  ' Redraw changed cells

    ' Schedule the next tick
    NextTick = Now + TimeValue("00:00:01")
    Application.OnTime NextTick, "GameLoop"
End Sub

' ——— Player movement (triggered by key events) ———
Sub MoveLeft()
    If PlayerCol > 1 Then
        ClearPlayer
        PlayerCol = PlayerCol - 1
        DrawPlayer
    End If
End Sub

Sub MoveRight()
    If PlayerCol < 10 Then
        ClearPlayer
        PlayerCol = PlayerCol + 1
        DrawPlayer
    End If
End Sub

Part 4: Preventing Flicker with ScreenUpdating

Updating many cells per frame causes visible flicker. Wrap all cell-drawing code with:

Sub RefreshDisplay()
    Application.ScreenUpdating = False  ' Freeze the screen

        ' ... all your cell drawing here ...

    Application.ScreenUpdating = True   ' Flush changes in one frame
End Sub

Common Pitfalls:

Forgetting StopTimer on workbook close — Add StopTimer to the Workbook_BeforeClose event to prevent orphaned timers crashing Excel.
Multiple timers stacking — Always store NextTick in a module variable so you can cancel it precisely with the fourth argument False.
Key bindings leaking — Call UnbindControls in both EndGame and Workbook_BeforeClose.

Summary

Master Application.OnKey for input and Application.OnTime for timing, combine them with ScreenUpdating = False for smooth rendering, and you have the complete engine that powers every Excel game — from Snake to Tetris.

Excel VBA Advanced: Keyboard & Timer Events for Games