The Arena level is found on D: 3-5. It can be immediately recognized by repeated messages saying "You hear the ecstatic cries of a large crowd!" As might be expected at a huge attraction like the Arena, there are vendors selling food on this level. It is home to several ratling traders, ratling rebel, the dwarf Nak An'Dwar, and Dak, the arena master.
The Arena itself is for combat practice, with the rewards for a successful fight being gold pieces. The rewards get larger as the PC wins more fights. A PC should not fight more than 19 times in the Arena before descending to deeper levels of the CoC. This is because she will encounter an NPC later (see 3.5.3.1) who assigns a quest to win the 20th Arena fight.
| Round | Possible opponents | ||||
|---|---|---|---|---|---|
| 1 | giant rat | kobold | rat | goblin | (giant rat) |
| 2 | giant rat | kobold | orc | goblin | (giant rat) |
| 3 | gnoll | hobgoblin | orc | rabid dog | (hobgoblin) |
| 4 | gnoll | orc scorcher | hobgoblin | skeleton | zombie |
| 5 | gnoll | orc scorcher | lizard man | fire beetle | giant bat |
| 6 | ghul | black hurthling | WILD CAT | wolf | giant bat |
| 7 | ghul | black hurthling | hyena | large kobold | jackal |
| 8 | ghul | orc scorcher | large gnoll | large kobold | bugbear |
| 9 | ogre | large orc | large gnoll | shadow | wererat |
| 10 | ogre | large orc | kobold chief | shadow | werewolf |
| 11 | large spider | cave fisher | orc chieftain | ankheg | gnoll chief |
| 12 | kobold shaman | dwarf | orc chieftain | ankheg | giant spider |
| 13 | kobold shaman | dwarf | orc chieftain | ankheg | giant spider |
| 14 | imp | displacer beast | orc chieftain | quasit | CAVE LION |
| 15 | cave bear | displacer beast | minotaur | hippogriff | jackalwere |
| 16 | cave bear | displacer beast | minotaur | hippogriff | jackalwere |
| 17 | cave bear | dire wolf | minotaur | harpy | giant lizard |
| 18 | cave bear | dark sage | tarantula | fire lizard | hell hound |
| 19 | cave bear | dark sage | tarantula | fire lizard | dark elven warrior |
| 20 | Li-Hon-Kai | Spardakius | Ripclaw | Bonk | (Li-Han-Kai) |

| Opponent | Race | ASCII | Remarks |
|---|---|---|---|
| Li-Hon-Kay | ogre magus | O | uses Invisibility and Frost Bolt, regenerates; alternate name Li-Han-Kay |
| Spardakius | minotaur | M | brute force |
| Ripclaw | troll | T | brute force |
| Bonk | hill giant | H | brute force |
Li-Hon-Kay (2/5 chance to appear) can be particularly annoying and dangerous. He regenerates health, casts invisibility, and attacks with frost bolts. PCs without cold resistance and the ability to see invisible will probably not survive a fight with Li-Hon-Kay. Fortunately, cold immunity and the ability to see invisible are granted by the Ancient Mummy Wrapping, an artifact armor held by Rehetep, the mummy lord (section 2.9.2.1). Players who want to be conservative and maximize the chances of survival in the 20th Arena fight will tackle the Pyramid first. Note also that although ogre magi are somewhat resistant to confusion, if one is successfully confused using Mindcraft, they are unable to become invisible. This works for Li-Hon-Kay as well as ordinary ogre magi. The other 20th fight Arena opponents will fall to offensive magic or simple brute force bashing.
The reward for winning the 20th Arena fight is an artifact sword, the Golden Gladius. It's needed to get Backstabbing, Two weapon combat, and especially the much desired Tactics
skill from Bart, or it can be used for the Demented Ratling in Dwarftown.
------- golden gladius "Death's Sting" (+2, 2d5+2) [+3, +3] (+7 spd) ------- Weight: 30s When worn it modifies DV by +3 and PV by +3. When used in melee combat it grants a +2 bonus to hit and causes 2d5+2 points of damage. When used as a missile it grants a -4 bonus to hit and causes 1d3 points of damage. It modifies your speed by +7. |
| Level: 1, DV: 22, PV: 12, Hits: 108, Attacks: 2, Damage: 1d8+12, Speed: 100. |
Note that it is possible to unintentionally cause Dak to become hostile during an arena fight, eg. if he is hit by a ball spell that reaches outside the front entrance of the Arena. Doing so will end the fight after a certain amount of turns, and cause the Arena Master to attack without giving a reward for the completed fight (and, of course, forfeit the possibility of any future fights and rewards).
Also, if you create a closed door on the tile the PC is teleported to after winning a fight, it will be opened and the message "You hear a short clapping sound." is displayed upon winning again. This is the only way to teleport on top of a door in ADOM, and according to the old bug tracker, said effect was intentionally coded for this sole possibility.

| Level: 1, DV: 16, PV: 0, Hits: 10, Attacks: 1, Damage: 1d6+1, Speed: 100. |
Ratling traders typically have more stock if their stock is uncursed or cursed – blessed stock seems to number at the low end of the range. In contrast to shops, which restock dependent on total game time passed, the ratling traders seem to restock dependent on game passed on the Arena level only. Thus a PC may go off adventuring for many days, return to the Arena and find no new food available. Wait or run around on the level for a while and the traders should eventually restock.
It is worthwhile to name the ratling traders according to the wares they sell. This prevents aimless searching for the traders who sell worthwhile food. They can also be slowed down with the Slow Monster spell, which will not turn them hostile.
| Level: 1, DV: 19, PV: 4, Hits: 18, Attacks: 1, Damage: 1d6+1, Speed: 100. |
Cats in the Arena are a special problem. If the PC wants the Ring of the Master Cat, directly killing cats must be avoided (section 0.9.2).
There are several ways to deal with cats in the Arena. Teleportation is one, from a wand or spell. Potions of exchange thrown at a cat will turn it into another monster. A cat can
be led over a trap until it is killed, teleported or turned into a writhing mass of primal chaos. However, if the PC sets off a trap which kills a cat, she is charged with
killing the cat. For this reason, as well as general tactical information, it is useful to know the layout of traps in the Arena when they are created. A map showing the traps
produced when the Arena is generated on D: 3 is shown below:
###############.###############
#0123456789AB0###456789AB01234#
#123456789AB0123456789AB012345#
#23456789AB0123456789AB0123456#
#3456789AB0123456789AB01234567#
###############################
0 - fireball 6 - arrow
1 - pit 7 - acid
2 - light 8 - pit (vipers)
3 - corruption 9 - spear
4 - stone block A - teleport
5 - alarm B - water
The pattern shifts, but otherwise remains the same, and can therefore be worked out by creating a single trap, when the Arena is generated on other levels.
Trap table has been removed in R+, all traps are random.
| Level: 1, DV: 15, PV: 9, Hits: 210, Attacks: 3, Damage: 2d8+8, Speed: 120. |