The D&D Monster battle arena

Version 1.1

The D&D battle arena was originally set up when “player versus player” duels were popular on esper.net but getting messy from a lack of a host for the battles and personal attachments to the characters used. The monster arena is for killing some time in a fun D&D battle while practicing combat mechanics. The objective is for players to learn how to effectively use abilities rather than a giant game of rock-paper-scissors.

Any battle requires 3 persons. 2 are the challengers, and one is the DM. It is the role of the DM to make any rules judgments and double-check the challengers’ actions.

To begin

The order of events

1. Arena selection

2. Monster limitations

3. Player decision on monster CR dice

4. Monster choices messages to DM, revealed when both are selected.

4b. Redraw (if necessary)

5. Battle modification is rolled

6. Battle commences

Arena selection

Dice roll	Arena name	Description
1	Energy Vortex	50’ cube with solid stone ground in the middle of an elemental vortex. Roll an extra d6 to determine energy type: 1: Fire. 2: Cold. 3: Electric. 4: Acid. 5: Sonic. 6: Negative Energy. Standing in the vortex area deals 20d6 of that energy per round. Starting distance is 1d10x5 feet.
2	Encircled by blades	Thirty foot circle, thirty feet high, infinite swirling blades outside that deal 20d6 damage per round a creature remains in this area. The blades bypass all damage reduction and can strike incorporeal. Starting distance is 1d6 times five feet.
3	Anti-magic arena	Fifty foot per side cube encompassed in an antimagic field. Starting distance is 1d10 times five feet.
4	The lake	Battle takes place on an infinite lake of water. There are two 10’ by 10’ islands floating 50’ apart for starting locations. The lake is 30’ deep universally. Blood in the water attracts half-dragon dire sharks in 1d3 rounds.
5	Disco from hell	50’ cube arena with strobe lights. First round: Lights are blindingly bright. Creatures opening their eyes suffer a -10 penalty on attack rolls and 1d6 damage. Second round: Normal illumination. Creatures that opened their eyes round one take a -5 penalty to attack rolls. Third round: Absolute darkness. Darkvision does not penetrate the darkness. Cycle repeats from round 1 next round.
6	Air-ena	Open air arena. If you can’t fly, you will hit the poisoned flaming adamantite spike covered ground 4 rounds after combat starts.

Monster limitations

By default, only mortal monsters are allowed (Outsider, elemental, fey, constructs and undead are prohibited). Monsters must be drawn from the core Monster Manual. This is modified by the limitations roll

Dice roll	Name	Description
1	Graveyard	Undead are allowed
2	Elemental	Elementals and constructs are allowed
3	Exclusive Club	Outsiders are allowed
4	Nature club	Fey are allowed
5	Nerd’s wet dream	Monster Manuals 1, 2, 3 and Fiend Folio are allowed
6	Roll twice	Roll twice, re-rolling 6s

Monster Selection

DM rolls 1d20, which is the upper limit for challenge rating of monster selection. Alternatively, the players may mutually agree upon a challenge rating rather than have the DM roll for it. Players may choose a monster below the challenge rating. Each player has five minutes to select a monster of that challenge rating or lower. Template monsters are NOT acceptable, even if the ‘example’ monster is of the proper CR. Game system is 3.5, so relevant errata applies to fiend folio and monster manual 2. Players message their selections to the DM, who reveals the selections at the end of the 5 minute time limit.

Redraw (Optional)

In the course of the players selecting their monsters, a pairing may occur where neither monster is able to hurt the other. An example would be an incorporeal creature whose only attack is negative energy, against a creature immune to negative energy that is unable to hurt an incorporeal creature. In this case, the DM may have both players redraw.

Alternatively, a pairing may occur where the one player has a ‘clear and obvious’ path to victory, such as complete immunity against all of the other player’s attacks. In this case, the DM will have the player in the unwinnable situation repack his monster without revealing the choice of the other player.

Battle Modification

Dice roll	Name	Description
1	Flat as a board	Vertical movement is disabled. Combat takes place on a flat plane.
2	Wild magic	Any spell-like ability, spell, or supernatural ability used has a 50% chance to affect the wrong target.
3	Magebane	Spells and spell-like abilities are disabled for this match
4	Full battle	Death/autokill effects (A mind flayer’s brain extraction, a flesh jelly’s absorption, a balor’s vopral sword) are disabled.
5	Swap	You use the monster that your opponent chose.
6	Neutered	Supernatural abilities are disabled for this match
7	Penetrated	Spell resistances are disabled for this match
8	Max	All variable numeric effects are maximized (including hit points)
9	Min	All variable numeric effects are minimized (lowest possible roll, including hit dice (1 per hit dice))
10	Roll twice	Roll twice, re-rolling 8s. Re-roll if max and min are selected.

House rulings so far

Burrowing: Burrowing is treated as ‘flying’ underground. Unless specifically stated, the burrowing creature leaves a tunnel that an opposing creature can follow. In this case, the battle becomes a tunnel as wide as the burrowing creature.

Ring-out: Causing a creature to leave the plane of existence, or to be taken to an area where travel back to the area is not possible, counts as a victory.

Stalling (Mechanic in process, will fully implement when more organized battles are set up) : In the interest of people not being cheap-assed, creatures are there to attempt to fight. If a player refuses to attack, they may forfeit the game at the DM’s discretion. For example, if a battle is a hawk VS a badger, and the hawk player refuses to attack, the DM may award victory to the badger. Similarly if the badger refuses to leave a burrowed position the hawk may be declared the winner.

Summoning

If the summoning ability is to summon another of the same creature (such as a Kelvezu (demon) summoning another Kelvezu, the death of either creature results in a loss.

If the summoning is of lesser creatures, such as a pit fiend summoning lemurs, or the use of a summon monster spell, then the death of the summoned creatures does not result in a loss.

The death or surrender of the ‘main’ creature ends the combat, regardless of existing summons. An exception to above is if the remaining summoned creatures have the capacity to ‘break’ the enchantment, such as with dispel magic, and are able to act before the main creature’s next action.

Intelligence

Your creature may act as intelligently as you wish. This is a battle of the monsters in terms of mechanics and strategy, not roleplay. Any arguments of “He can’t do that, his creature isn’t smart enough to do that” will not be accepted.