Yetis never charging

Verified against the spelunky.ai port v0.1.11 on 28 October 2026.

A Yeti is written to charge, as a Caveman does: it has a charge, at 3 pixels a step, and it sends sight checks ahead of it every 6 steps. But when a sight check reaches the player, it sets off only the Cavemen and Hawkmen near him, so a Yeti's sight can set off a Caveman, but never a Yeti. The only thing that sets a Yeti charging is a Piranha's bite, and no generated level has both.

A Yeti's sight check reaches the player, and a Caveman walled in under him starts charging. The Yeti that saw him never charges: it walks up and throws him ^[1].

A Yeti's create event names its charge, ATTACK = 2 ^[2], and its step runs it: 3 pixels a step the way it faces, turning at walls ^[3]. While it stands or walks, it sends a sight check, oEnemySight, every 6 steps ^{[4] [5]}. The check's collision with the player is what sets monsters charging:

with oCaveman
{
    if (distance_to_object(oPlayer1) < 100 and status < 98)
    {
        status = 2;
        playSound(global.sndAlert);
    }
}

The same follows with oHawkman, and there's no with oYeti ^[6]. So the Yeti's sight sets off the Cavemen and Hawkmen within 100 pixels of the player, and never a Yeti. The only code that sets a Yeti's status to 2 is a Piranha's bite: a Piranha goes for the nearest live Caveman, or with none the nearest Shopkeeper, Hawkman or Yeti, if it's swimming, and sets what it reaches charging ^[7]. Piranhas live only in the Jungle and Yetis only in the Ice Caves ^[8].

Let any Yeti in the Ice Caves see the player: it walks up to him, and never charges. The replay of the clip's staged scene, a custom level, has a Yeti on the player's floor and a Caveman walled in under him. The Yeti's sight check reaches the player, and the Caveman, which can't see him, charges; the Yeti walks on, sends more checks, and throws him when it reaches him ^[9]. In another custom level, with a Yeti swimming in a pool with two Piranhas and nothing else for them to go for, their bite sets it charging, turning at the walls ^[10].

The spelunky.ai port reproduces it exactly: it's in docs/quirks.md's list of the 1.1 source's bugs ^[8], and the oracle's fingerprint of both replays pins who charges. No option turns it off.