A comprehesive list of all keyboard and mouse commands.

Keyboard And Mouse

These basic key presses are typical for computer players using a US-version keyboard and may not be the same UK-version keyboards, different computer formats (eg: Mac), smart-phone users, game consoles, emulators, etc.
Definitions

LMB = Left mouse button.
RMB = Right mouse button.
Ctrl = Control keyboard button.
Shft = Shift keyboard button.
Alt = Alt keyboard button.
SB = Spacebar keyboard button.

key1 + key2 or key1 - key2 = press and hold key1, press key2, release both.
drag + key1 = press and hold key1 and move mouse to new area, release key1.

Universal Commands

Enter = confirm action.
ESC = disregard action.
F1 = UFOpaedia menu.
RMB on icon = its UFOPAEDIA entry.
SB = pause or resume time.
0 ↔ 5 = time controls.
TAB = overhead or isometric view.
Alt+P = screenshot as a PCX file.

Cityscape

RMB = centre here when overhead view.
O = options menu.
ESC = quit game.
Enter = highlight last message location.

Tab Bar

Agent & Vehicle Tabs

Double LMB = highlight and centre selected subject on cityscape.
Ctrl-LMB = select multiple (max 13).
RMB = remove from temporaty group.
Ctrl-LMB = add waypoint.
Shft-LMB = go to building.

Vehicle Tab

M = manual vehicle control (see below for commands).
Alt-LMB = attack selected building or vehicle.

Organisation Tab

LMB = hightlights and centres buildings owned.

Battlescape

View

PgUp = go up one view level in elevation.
PgDn = go down one view level in elevation.
Home = center on selected unit.

Movement

RMB = (agents static) turn to face a new direction.
RMB = (agents moving) cancel a move order.
Alt-LMB = move-to-here when destination is already occupied by another unit.
F2 = crawl
F3 = walk
F4 = run
BKSP = crouch
J-LMB in the air next to the ledge or railing, release. To make a unit jump off/over something.
Ctrl-LMB = add waypoint (maximum 5).
LMB Click+Drag cursor over units on the battlescape to quickly select multiple units irrelevant of which group they are in.

Attitude

F9 = safe
F10 = cautious
F11 = agressive

Targeting

RMB on a non X-Com unit to highlight them as a target.
Shft-LMB force an agent to fire at this cursor location.
F5 = hold fire
F6 = aimed shot
F7 = snap shot
F8 = auto shot

Items

RMB on explosive item in hand to set 'detonate on impact'.
[ = drop item left hand.
] = drop item right hand.
' = throw item left hand.
\ = throw item right hand.
ENTER = open inventory of selected agent.
Y/N = accept/decline current timer setting on explosive device.

Agent Equip Screen

Ctrl-LMB = allows selecting multiple units.
TAB = changes attributes mini-screen.
A = switch to armor screen.
E = switch to equipment screen.

Vehicle Quip Screen

1 = Select GUNS screen.
2 = Select ENGINES screen.
3 = Select DEVICES screen.

Cityscape Waypoints

Waypoints may be given to airbourne or road vehicles.

Switch to overhead view.
Give a vehicle a target destination (this can include "Attack" command).
Click the "Move to Destination" button (next to "Move to Building" button).
Hold down the control button (Ctrl) and LMB click somewhere on the overhead cityscape to add a waypoint.
The yellow line shows the path the vehicle will take after you release the button.
Close the mini screen with the "X", if it appeared.

Hold Fire Forced Fire

If hold fire is used (the "X" in shot types), but something needs to be shot:

click LMB on agents weapon in their hand, white outline, click LMB on anything or
hold down shift, click LMB on anything.

Constant fire is possible if you hold down LMB.
There is an error for an agent's actions if the target was selected via RMB.

Manual Control

PgUp = Increase Speed
PgDn = Decrease Speed
Home = Increase Altitude (flying), U-Turn (road)
End = Decrease Altitude (flying) , Swap lanes(road)
LMB = aim weapon at cursor and fire
RMB = set direction

Quick Reference

Keyboard & Mouse Controls on StrategyCore.

Input Device Reference (Apocalypse)