Event codes
| Code | Explanation | Example Cards |
|---|---|---|
| 0x01 | Unknown | Island Fish Jasconius |
| 0x04 | Upkeep related | Copper Tablet |
| 0x0A | Draw phase | Howling Mine |
| 0x15 | Creature attacks | Hasran Ogress |
| 0x1A | Attacking creature is not blocked | Murk Dwellers |
| 0x1F | Unknown | Library of Leng |
| 0x22 | Upkeep related | Copper Tablet, Juzam Djinn, Winter Orb |
| 0x32 | Calculate power | Kird Ape |
| 0x33 | Calculate toughness | Kird Ape |
| 0x34 | Update keyword abilities | Goblin King and other lords |
| 0x3B | Used by AI to evaluate pump effects and damage prevention effects | Morale, Samite Healer |
| 0x3C | Changes land type | Blood Moon, Evil Presence |
| 0x6A | Unknown | Pacifism |
| 0x6C | Cast spell | Any sorcery, instant, or interrupt |
| 0x6D | Activate ability (pay costs, select targets) | Any card with an activated ability |
| 0x6E | "Stacking" damage trigger? | Hypnotic Specter, Pit Scorpion, Spirit Link |
| 0x71 | Resolve spell | Any non-permanent spell |
| 0x72 | Resolve activated ability | Any card with an activated ability |
| 0x73 | Check if activated ability can be played (mana and targets available). | Any card with an activated ability |
| 0x74 | Check if spell can be played | Any sorcery, instant, interrupt. Also some permanents, such as auras and Clone. |
| 0x77 | Going to graveyard | Su-Chi |
| 0x78 | Check possible blocking. Used to implement non-keyword evasion abilities. | Juggernaut, Pacifism |
| 0x79 | Check if creature can attack | Pacifism, Sea Serpent |
| 0x7D | Check if triggered ability should trigger | Any card with a triggered ability |
| 0x7E | Resolve triggered ability | Any card with a triggered ability |
| 0x7F | Resolve mana ability | Any card with a mana ability |
| 0x81 | Card becoming tapped (0x91 seems to do the same thing) | City of Brass |
| 0x82 | Untap phase. Can be used to prevent untapping. | Winter Orb, Willow Satyr |
| 0x84 | Unknown | Island Fish Jasconius |
| 0x85 | Upkeep cost | Force of Nature, Masticore |
| 0x86 | Compulsory upkeep effect, often result of an upkeep cost that the player choose not to pay | Stasis, Force of Nature, Copper Tablet |
| 0x87 | Unknown | Serendib Djinn, Lord of the Pit |
| 0x89 | Declare attackers? | Juggernaut |
| 0x8A | Unknown | Llanowar Elves, Serendib Djinn |
| 0x8B | Unknown | Llanowar Elves, Serendib Djinn |
| 0x8C | AI handling activated ability that gives first strike? | Noble Panther, Rainbow Knights |
| 0x8F | Unknown | Mana Batteries |
| 0x90 | Unknown, creatures with unusual activated abilities | Priest of Yawgmoth, Samite Healer, Cuombajj Witches, Dragon Whelp, anything that regenerates |
| 0x91 | Unknown (but see 0x81) | City of Brass |
| 0xA0 | Unknown | Library of Leng |
| 0xA1 | Unknown | Library of Leng |
| 0xC7 | AI stuff |
