The Basics:
DTV stands for Defend The Viscount. The game mode used to be called Defend The Virgin and before that, Defend the Village. Viscount Valdemar is a bearded gentleman in a fur hat who must be defended against waves of more and more powerful attackers (bots) by the players. He can't move but he can fight a little with a dagger. DTV game mode works a little differently from the others: you don't get a multiplier, instead you get gold and XP when the round ends, after three waves of attackers. The amount you get depends on how tough the bots are, how quickly you beat them and how many of you are still alive. If Viscount Valdemar is wounded, your reward is slightly less. Pink text will appear to warn you that he is being attacked. At the end of each wave, all horses die, so although you can bring a horse it will die after the first wave. Siege equipment cannot be used at all. Usually somewhere near the Viscount is a box tagged Equipment. You can use this to repair or replace your gear, although doing so will eventually use it up. Press F or whatever key you use to open doors to use it. Although there is no siege equipment, a lot of maps feature a ballista or two. To use one, choose Pull the crank, Arm ballista (or Use ballista) and then Take aim. Ballistae can often kill 2 or 3 bots at once, but they need practice to aim properly.
Tips:
A Shieldwall is important on most maps. The best kind of shieldwall is both shielders and hitters, with 2H and polearm str builds as the best hitters. Shielders in the wall are best simply standing still and taking the hits - you might want more than one shield per player if the bots have weapons that can break shields easily. Once you are part of a shieldwall, don't leave it! If you do, you risk letting the bots through to attack the others from behind. Don't stand too close behind a shieldwall so that you back-block attacks and don't be too hungry for kills for yourself: winning is what matters.
Map by Map
Istiniar
Description: This is a modifed version of the village of Istiniar. The Viscount stands in a field on the edge of the village. There are two ballistae nearby and the bots spawn from opposite directions at either end of the village. There is a ladder up to the roof of one of the buildings in the middle of the village.
Tactics: The bots spawning on your right will arrive sooner than the ones spawning on your left. They will often split into two groups, a larger one moving into the middle of the village and a smaller one, usually only 2 or 3 bots, coming up the hill towards the ballistae. You can block the larger group on the right with a shieldwall. Archers and crossbows can climb the ladder and shoot from the roof, but they should stay alert as bots will often climb the ladder and attack them. If a good shielder can pull the second, left side group of bots into a corner this makes things much easier.
Arena
Description: An arena (obviously) Bots spawn from three directions, one of which is a raised wooden walkway. There are steps up to a platorm opposite this route used by the bots.
Tactics: For most teams, this is just a horrible map. Unless you have around 10 shielders or more, all you can do is have a straight fight and kill the bots before they kill you, which quickly becomes impossible. If you do have enough shields, your only tactic is to form three shield walls, one for each spawn, which can win quite a lot of rounds for you.
DTV Helms Deep
Description: A fortress with ballistae, a wall and a river running out of a gate. There are stairs leading up to battlements on the wall and ladders on the other side of the wall.
Tactics: The bots will either climb the ladders and attack the battlements or wade through the river and attack through the gate (which does not close) If you fight in the river, watch your breath bar or you may drown: the water is shallow enough so that you can reset your bar by jumping. Block the bots for long enough here and some of them may drown. Fighting on the battlements and on the staircase may difficult if you are using long 2H weapons or polearms. Watch out for bots shooting the viscount from the top of the stairs, too. One problem with the map is that bots on horses often get stuck against a fence on the map edge or just stuck among all the horses at the ladders. Be careful of being shot if you go out to kill them.
DTV Battlemasters
Description: A fortress town dominated by two large towers with round stone passages overhead connecting them and which overlook a wide road with stairs at each end. The Viscount is in front of double doors and guarded by 4 ballistae. On the left seems to be a row of market stalls, on the right is another road cut in half by a low wall. Bots attack from all 3 directions.
Tactics: Most players hate this map because once again there is little you can do to stop the bots getting to the Viscount: it's just a straight fight. One thing that can help is getting a good shielder into the corner of the steps, but he won't pull many bots to himself. To make things even worse the map is large and very slow and one or two bots will always always stick at the middle spawn. Be careful if you go to kill them - if this isn't the last wave remember that the bots spawn very close.
Grunwalder Castle
Description: A modified version of Grunwalder - the Viscount is in front of a castle keep at the top of some steps. One group of bots will spawn on the castle walls opposite him and a larger group will spawn near the castle gates and charge up the hill.
Tactics: Split into two teams, one to fight the bots on the walls and the other to form a shieldwall across the steps. Archers and crossbows can shoot from the sides. Make sure both teams stay strong enough to do their work. This map is much easier with a large number of players.
Ballista Madness
Description: A wide open grassy map with trees at the edge. The players and the Viscount are in a wooden walled area with lots of ballistae aiming out. There is a mountain pass behind. Bots spawn ahead and to the right. The equipment box is on the left side.
Tactics: In spite of the name, the ballistae are not much use to you. This isn't an easy map, but it isn't quite a straight fight because bots will stick against a big fallen tree on the right side and cavalry bots will often stick against the walls too. The most important thing is not to let bots kill the viscount while you are away fighting somewhere else on the map.
DTV Sea Raid
Description: This is the sea raid map from Siege with a few changes. A fortified town with 3 doors and a gate overlooks sea cliffs. Bots spawn outside the walls, in front of the nearest door to the Viscount and in the field in front of the gate. The equipment box is under the walkway behind the Viscount. Note that the door nearest the cliffs isn't used in the DTV version and there are only two roofs that you can get onto.
Tactics: Many players think that this is the best map and it's the only one I've ever seen where the team has beaten every wave of bots. The tactics are simple: two shieldwalls, one at each door. Once all the bots here have been killed, the best fighters should run round to the gate and start killing them there before someone opens the gate to let them in and finish killing the bots inside the walls. Only open the gate when you think your team is strong enough: usually this will be when about 10-15 bots are left, perhaps a lower number on later rounds but it will depend on how many players are left. Opening the gate too soon is a sure way to lose. Avoid also trapping your teammates outside the gate to be killed by the next wave. At the time of writing, there is a glitch where you can stick bots outside by jumping over a fence against the wall: admins may kick you for doing this as it's considered cheating.
DTV Mein Bridge
Description: A mine with a deep chasm filled with water and one very wide and one very narrow bridge across it. Bots come from the other side but also down some steps behind from outside the mine.Two ballistae watch the wide, left side bridge.There is a blacksmith's forge on the right - the equipment box is here.
Tactics: The bridge on the right is wide and it is hard to block it with a shieldwall, although steps slow any bots that do get across. You need to split into 3 teams, the strongest to fight on the wide, left side bridge, a smaller group to block the narrow bridge and another small group to fight on the stairs behind. Make sure that you keep these 3 groups strong enough to do their work or the bots will get to the viscount. Cavalry bots will often ride over the edge of the chasm, killing their horses and drowning in the water, but occasionally one of them will stick halfway down and have to be shot. These stuck bots can be hard to see sometimes. Bots also stick on the edge of the narrow bridge and can be kicked off to their doom. Although this map is quite fun in some ways, it's hard to get very far here because defending the left side is not easy.
Celtic Ruins
Description: The ruins of a castle, with the Viscount standing in front of a small church. Outside the castle walls is a field and a bridge across a river. Bots spawn from here and attack through a gate beyond two ruined towers (each of which has a ballista, which won't really be used) and also from a tower at the end of a path on the right, guarded by a ballista. There is also a wooden platform at the top of some steps with another ballista.
Tactics: Two teams are needed, one to fight the smaller group spawning at the tower and another - the most important - to form a shieldwall between the two towers on the left. Be careful, as the bots from the outside come in two groups and you can think you have killed them all only for more to attack you. The ballista guarding the path is useful, the the one on the platform isn't. Archers and crossbows are best standing on the two towers. No matter how much you want kills yourself, don't run round the the towers and attack the bots from the left and right unless you are sure they are nearly all dead: the one way to lose this map quickly is to pull lots of bots away from the shieldwall then get killed so that the bots turn round, climb the towers to slaughter the archers and attack the shieldwall in the back!
Thermopylae
Description: A rocky island out at sea with a single road. The Viscount is on the road, guarded by a wooden platform with two ballistae. Bots will charge round the corner from the other end of the road.
Tactics: Lots of players like this map because it's quick and easy: form a shieldwall between the cliff and the platform, archers, crossbows, throwers shoot the bots from the platform. Anyone not in the shieldwall wait behind to kill any bots that get through. That's it. Bots sometimes glitch and ride into the platform.
Desert Mountains
Description: A mountain pass with ballistae at the top.
Tactics: This isn't an easy map but it is possible to form a shieldwall halfway across the pass, or form an unusual shield wall in a semicircle against one cliff wall. The best place to form a wall is at the top of the steepest slope so that cavalry bots are slowed. Be careful not to teamkill with the ballistae.