Keep your League of Legends side-button setup small. Map one action you already use to a button you can press without moving your hand, test it while you move, and add another only after the first one works. No single mapping is right for everyone, because your grip and where the buttons sit decide what you can reach.
Choose a small set from actions you already use
Start with your current Keybindings menu, not a list copied from someone else. Pick one action you already press often and know well, so the only new thing you learn is where your thumb goes. Changing the action and the button at the same time makes it hard to tell what went wrong.
Next, pick the input. League's in-game options accept Mouse 1 through Mouse 5, and Riot's in-game mouse-button limit says buttons beyond Mouse 5 are not detected by the game and can't be bound through those options. Mouse 1 and Mouse 2 already handle your main clicks, so the two thumb buttons that register as Mouse 4 and Mouse 5 are your practical side-button choices in the menu.
One optional way to start: put your first action on Mouse 4. Leave Mouse 5 empty until you have a second action you actually need. If reaching it makes your thumb stretch or your palm lift, leave it unbound. Shape matters here, and our LoL mouse fit checklist covers grip and comfort checks if neither button feels natural.
Extra buttons don't change this rule. Many gaming mice for League of Legends have more side buttons than the game's in-game menu can use. If you own a denser layout, our guide to mice with six side buttons explains how thumb fit and binding density interact.
Bind one input, then test it while moving
Set up a single side button in your in-game options first, then confirm that you can trigger it repeatedly without losing mouse control during movement.
- Write down the action's current input. You'll need it if the new bind doesn't work out.
- Open the menu in game. Press Esc to open Options, then go to Keybindings. Riot confirms this route and lists Mouse 1 through 5 as usable inputs in its Keybindings FAQ.
- Assign the button. Select the action's bind slot and press the side button. The slot should now show the mouse input instead of the old key.
- Test it in a low-pressure game, such as a custom game. Press the bind many times while you keep moving with your usual clicks. Watch for three things: every press registers, your grip stays where it started, and your movement stays controlled.
- Keep, change, or remove it. If all three hold, keep the bind. If presses miss, your hand shifts, or movement gets sloppy, try the other side button or a different action. You can also put the old input back.
- Add a second bind only after the first one passes. Run the same test on it by itself, so you know which change caused any problem.
If you kite with attack-move, include that pattern in your test. Our attack-move keyboard setup walks through that bind on the keyboard side. A thumb that rests near a DPI button can also cause accidental presses during the test. In that case, see our guide to DPI button placement and remapping before you blame the side-button bind.
FAQs
What if the mouse button I want to bind is beyond Mouse 5?
League won't see it through the in-game menu. Riot's stated in-game limit is that buttons beyond Mouse 5 are not detected by the game and can't be bound through the in-game options. Pick a button that registers as Mouse 4 or Mouse 5 instead, or use a keyboard key for that action.
Can I change keybindings from the League client instead?
Yes. Riot's FAQ gives a client Hotkeys route as well: in the League Client Update, click Settings (the gear icon in the top right corner of the window), then click Hotkeys. This works when you want to set things up before you load into a game.
Does Restore Defaults undo just one test bind?
No. Riot describes Restore Defaults as removing your customization and going back to the standard keybindings, so it resets more than one test. To undo a single bind, open that action's slot and enter the input you wrote down before the change.
