Series

Prince of Persia

15 games, 1989–2024.

Games

Mechanics

Mechanic	Prince of Persia 1989
Air control	Fixed
Fall damage	Stepped by speed
Gravity	NoneOne gravity
Jump	Table
Ledge grab	Button held

A marked cell changed from the game before. “Uses” means the game has the mechanic, with no variant recorded yet.

Every claim, by mechanic and game

Concept	Prince of Persia 1989
Air control	`GENCTRL`, which turns the player's input into moves, picks its branch by the frame the kid shows (standing, starting a run, running, starting a jump up, hanging, turning, or crouching). The frames of the standing and running jumps, 16 to 44, match none of them, and it returns without reading the joystick, so a jump can't be steered once it starts. Code
Fall damage	A landing's cost goes by the kid's downward speed when he reaches a floor: under 22 (`OofVelocity`) he lands softly; from 22 up to 33 (`DeathVelocity`) he loses 1 hit point and dies if it was his last; at 33 he loses 100, and dies. A guard who lands at 22 or more dies, and the shadow lands softly at any speed under 33. Code Computed from the fall sequence and gravity: a kid who steps off a ledge has fallen 30 px when the free fall starts at speed 15, and reaches the floor below at speed 21 after one floor (63 px), 30 after two, and 33 after three or more. One floor costs nothing, two cost a hit point, and three or more kill him. The count assumes `weightless` is clear and that a fall crossing to the screen below keeps its speed and its distance to the next floor, which the atlas hasn't read in the screen-change code. Code
Gravity	With the `weightless` flag clear, a fall (action 4) adds 3 px per cycle to the kid's downward speed, up to 33 px per cycle (`AccelGravity`, `TermVelocity`); with it set, gravity is 1 and the cap 4 (`WtlessGravity`, `WtlessTermVel`). The fall sequences that start it set the speed to 15 (`setfall`). In any other action, including the jumps' (action 1) and a fall's first frames (action 3), gravity does nothing. Code
Jump	The kid's horizontal position, `CharX`, counts in units of 14 to a block: the left edges of the blocks (`BlockEdge`) step by 14, and the screen is 140 units wide, so it holds 10 blocks (computed). A floor is 63 px tall (`BlockHeight`). Code Both of the kid's jumps are fixed sequences in `SEQTABLE.S`, with no speed or gravity: each cycle `ANIMCHAR` reads the sequence up to the next frame number, adding each `chx` byte to `CharX` in the direction he faces and each `chy` byte to his height. The frames of both jumps add no horizontal offset of their own (`Fdx` 0 in `FRAMEDEF.S`). Code The standing jump (`standjump`) runs frames 16 to 33. Its `chx` steps are 2, 2, 2, 2, 2, 7, 9, 5, 1, 4, −3, 5, and 1 units, 39 in all (computed); its only `chy` steps lift the kid 6 px and set him back down on the next frame. Frames 20 to 25 lack the floor-check bit, so `onground` doesn't test the floor under him there, and the steps between frame 19 and frame 26 move him 28 units, 2 blocks (computed). Code The running jump (`runjump`) runs frames 34 to 44. Its `chx` steps are 5, 6, 3, 5, 7, 12, 8, 8, 4, 4, and 5 units, 67 in all (computed), and its `chy` steps raise the kid 14 px over three frames and lower him 14 px over the next two. Frames 39 to 43 lack the floor-check bit, and the steps between frame 38 and frame 44 move him 43 units, 3 blocks and 1 unit (computed). Code In a run (frames 4 to 14), `arunning` reaches the running jump only while the joystick is held forward (centered stops the run, back turns it), and then only on a fresh press of up (`clrU` negative), with forward and up the names Mechner's comments give the joystick signs; in a full run (frame 7 or later) that calls `DoRunjump`, which Mechner's comment describes as "Calibrate jump so that foot will push off at edge". It looks for a gap or spikes in the next two blocks and measures from the kid's position 4 units on to that floor's end. When the end is 6 to 15 units off, it moves him so the jump starts with `CharX` 14 units (one block) short of the end (computed). Farther off, it returns without jumping (comment: "still too far away--wait till next frame"); nearer, it moves him 1 unit (computed) and jumps (comment: "He jumped too late; he'll miss edge"). With no gap in sight, he jumps where he is. Code
Ledge grab	A falling kid grabs a ledge while the button is down (either Apple II button, unless manual control splits them) and he is alive, his downward speed is under 32 px per cycle, and his feet are within 25 px above the floor plane he is falling toward. `fallon` then tests for a ledge 8 units behind him (`grabreach`), requiring clear space above it and a floor piece in front, and on a catch it aligns him to the block, stops his fall, and starts the hang. It runs on the first frames of a fall (102 to 105) and through the free fall. Code